L. Clark - Susquehanna University

L. Clark
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Name
L. Clark
Affiliation
Susquehanna University
City
Selinsgrove
Country
United States

Pubs By Year

Pub Categories

 
Mathematics - Rings and Algebras (11)
 
Quantum Physics (10)
 
Physics - Optics (9)
 
Nuclear Experiment (8)
 
Mathematics - Operator Algebras (8)
 
Physics - Strongly Correlated Electrons (4)
 
Physics - Materials Science (3)
 
Mathematics - Dynamical Systems (2)
 
High Energy Physics - Phenomenology (2)
 
Physics - Superconductivity (1)
 
Physics - Atomic Physics (1)
 
Physics - Instrumentation and Detectors (1)
 
Physics - Statistical Mechanics (1)
 
Nonlinear Sciences - Pattern Formation and Solitons (1)
 
High Energy Physics - Experiment (1)
 
High Energy Physics - Theory (1)
 
Mathematical Physics (1)
 
Mathematics - Combinatorics (1)
 
Mathematics - Mathematical Physics (1)

Publications Authored By L. Clark

2017May
Authors: D. Ho, P. Peng, C. Bass, P. Collins, A. D'Angelo, A. Deur, J. Fleming, C. Hanretty, T. Kageya, M. Khandaker, F. J. Klein, E. Klempt, V. Laine, M. M. Lowry, H. Lu, C. Nepali, V. A. Nikonov, T. O'Connell, A. M. Sandorfi, A. V. Sarantsev, R. A. Schumacher, I. I. Strakovsky, A. Švarc, N. K. Walford, X. Wei, C. S. Whisnant, R. L. Workman, I. Zonta, K. P. Adhikari, D. Adikaram, Z. Akbar, M. J. Amaryan, S. Anefalos Pereira, H. Avakian, J. Ball, M. Bashkanov, M. Battaglieri, V. Batourine, I. Bedlinskiy, W. J. Briscoe, V. D. Burkert, D. S. Carman, A. Celentano, G. Charles, T. Chetry, G. Ciullo, L. Clark, L. Colaneri, P. L. Cole, M. Contalbrigo, V. Crede, N. Dashyan, E. De Sanctis, R. De Vita, C. Djalali, R. Dupre, A. El Alaoui, L. El Fassi, L. Elouadrhiri, G. Fedotov, S. Fegan, R. Fersch, A. Filippi, A. Fradi, Y. Ghandilyan, G. P. Gilfoyle, F. X. Girod, D. I. Glazier, C. Gleason, W. Gohn, E. Golovatch, R. W. Gothe, K. A. Griffioen, M. Guidal, L. Guo, H. Hakobyan, N. Harrison, K. Hicks, M. Holtrop, S. M. Hughes, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, D. Jenkins, H. Jiang, H. S. Jo, K. Joo, S. Joosten, D. Keller, G. Khachatryan, A. Kim, W. Kim, A. Klein, V. Kubarovsky, S. V. Kuleshov, L. Lanza, P. Lenisa, K. Livingston, I . J . D. MacGregor, N. Markov, B. McKinnon, T. Mineeva, V. Mokeev, R. A. Montgomery, A Movsisyan, C. Munoz Camacho, G. Murdoch, S. Niccolai, G. Niculescu, M. Osipenko, M. Paolone, R. Paremuzyan, K. Park, E. Pasyuk, W. Phelps, O. Pogorelko, J. W. Price, S. Procureur, D. Protopopescu, M. Ripani, D. Riser, B. G. Ritchie, A. Rizzo, G. Rosner, F. Sabatié, C. Salgado, Y. G. Sharabian, Iu. Skorodumina, G. D. Smith, D. I. Sober, D. Sokhan, N. Sparveris, S. Strauch, Ye Tian, B. Torayev, M. Ungaro, H. Voskanyan, D. P. Watts, M. H. Wood, N. Zachariou, J. Zhang, Z. W. Zhao

We report the first beam-target double-polarization asymmetries in the $\gamma + n(p) \rightarrow \pi^- + p(p)$ reaction spanning the nucleon resonance region from invariant mass $W$= $1500$ to $2300$ MeV. Circularly polarized photons and longitudinally polarized deuterons in $H\!D$ have been used with the CLAS detector at Jefferson Lab. The exclusive final state has been extracted using three very different analyses that show excellent agreement, and these have been used to deduce the {\it{E}} polarization observable for an effective neutron target. Read More

In the vanadium oxyfluoride compound (NH$_4$)$_2$[C$_7$H$_{14}$N][V$_7$O$_6$F$_{18}$] (DQVOF), the V$^{4+}$ (3d$^1$, $S=1/2$) ions realize a unique, highly frustrated breathing kagome lattice composed of alternately-sized, corner-sharing equilateral triangles. Here we present an $^{17}$O NMR study of DQVOF, which isolates the local susceptibility of the breathing kagome network. By a fit to series expansion we extract the ratio of the interactions within the breathing kagome plane, $J_\triangledown / J_\vartriangle = 0. Read More

We consider the baker's map $B$ on the unit square $X$ and an open convex set $H\subset X$ which we regard as a hole. The survivor set $\mathcal J(H)$ is defined as the set of all points in $X$ whose $B$-trajectories are disjoint from $H$. The main purpose of this paper is to study holes $H$ for which $\dim_H \mathcal J(H)=0$ (dimension traps) as well as those for which any periodic trajectory of $B$ intersects $\overline H$ (cycle traps). Read More

This paper uses a quantum image detector method to model light scattering on flat surfaces which range from perfectly-reflecting to highly-absorbing mirrors. Instead of restricting the Hilbert space of the electromagnetic field to a subset of modes, we double its size. In this way, the possible exchange of energy between the electromagnetic field and the mirror surface can be taken into account. Read More

Both classical and quantum waves can form vortices: with helical phase fronts and azimuthal current densities. These features determine the intrinsic orbital angular momentum carried by localized vortex states. In the past 25 years, optical vortex beams have become an inherent part of modern optics, with many remarkable achievements and applications. Read More

2017Mar
Authors: CLAS Collaboration, I. Bedlinskiy, V. Kubarovsky, P. Stoler, K. P. Adhikari, Z. Akbar, S. Anefalos Pereira, H. Avakian, J. Ball, N. A. Baltzell, M. Battaglieri, V. Batourine, A. S. Biselli, S. Boiarinov, W. J. Briscoe, V. D. Burkert, T. Cao, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, G. Ciullo, L. Clark, L. Colaneri, P. L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, R. Dupre, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, E. Fanchini, G. Fedotov, R. Fersch, A. Filippi, J. A. Fleming, T. A. Forest, M. Garçon, N. Gevorgyan, Y. Ghandilyan, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, C. Gleason, E. Golovatch, R. W. Gothe, K. A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, N. Harrison, M. Hattawy, K. Hicks, S. M. Hughes, C. E. Hyde, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, D. Jenkins, H. Jiang, H. S. Jo, K. Joo, S. Joosten, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, A. Kim, W. Kim, F. J. Klein, S. E. Kuhn, S. V. Kuleshov, L. Lanza, P. Lenisa, K. Livingston, I. J. D. MacGregor, N. Markov, B. McKinnon, Z. E. Meziani, M. Mirazita, V. Mokeev, R. A. Montgomery, A. Movsisyan, C. Munoz Camacho, P. Nadel-Turonski, L. A. Net, A. Ni, S. Niccolai, G. Niculescu, M. Osipenko, A. I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, E. Pasyuk, P. Peng, W. Phelps, S. Pisano, O. Pogorelko, J. W. Price, Y. Prok, D. Protopopescu, A. J. R. Puckett, B. A. Raue, M. Ripani, A. Rizzo, G. Rosner, P. Rossi, P. Roy, F. Sabatié, M. S. Saini, C. Salgado, R. A. Schumacher, Y. G. Sharabian, Iu. Skorodumina, G. D. Smith, D. Sokhan, N. Sparveris, S. Stepanyan, I. I. Strakovsky, S. Strauch, M. Taiuti, Ye Tian, B. Torayev, M. Turisini, M. Ungaro, H. Voskanyan, E. Voutier, N. K. Walford, D. P. Watts, X. Wei, L. B. Weinstein, M. H. Wood, M. Yurov, N. Zachariou, J. Zhang, I. Zonta

The cross section of the exclusive $\eta$ electroproduction reaction $ep\to e^\prime p^\prime \eta$ was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections $d^4\sigma/dtdQ^2dx_Bd\phi_\eta$ and structure functions $\sigma_U = \sigma_T+\epsilon\sigma_L, \sigma_{TT}$ and $\sigma_{LT}$, as functions of $t$ were obtained over a wide range of $Q^2$ and $x_B$. Read More

2017Mar
Authors: P. Collins, B. G. Ritchie, M. Dugger, A. V. Anisovich, M. Döring, E. Klempt, V. A. Nikonov, D. Rönchen, D. Sadasivan, A. Sarantsev, K. P. Adhikaria, Z. Akbar, M. J. Amaryana, S. Anefalos Pereira, H. Avakiana, J. Ball, I. Balossino, M. Bashkanova, M. Battaglieri, I. Bedlinskiy, A. S. Bisellik, W. J. Briscoe, W. K. Brooks, V. D. Burkert, Frank Thanh Cao, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, T. Chetry, G. Ciullo, L. Clark, L. Colaneri, P. L. Cole, N. Compton, M. Contalbrigo, O. Cortes, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, E. Fanchini, G. Fedotov, A. Filippi, J. A. Fleming, Y. Ghandilyan, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, D. I. Glazier, C. Gleason, E. Golovatch, R. W. Gothe, K. A. Griffioen, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, N. Harrison, D. Heddle, K. Hicks, M. Holtrop, S. M. Hughes, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, D. Jenkins, H. S. Jo, S. Joosten, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, A. Kim, W. Kim, A. Klein, F. J. Klein, V. Kubarovsky, L. Lanza, P. Lenisa, K. Livingston, I. J. D. MacGregor, N. Markov, B. McKinnon, C. A. Meyer, M. Mirazita, V. Mokeev, R. A. Montgomery, A Movsisyan, C. Munoz Camacho, G. Murdoch, P. Nadel-Turonski, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, A. I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, E. Pasyuk, W. Phelps, S. Pisano, O. Pogorelko, J. W. Price, Y. Prok, D. Protopopescu, B. A. Raue, M. Ripani, A. Rizzo, G. Rosner, P. Roy, F. Sabatié, C. Salgado, R. A. Schumacher, Y. G. Sharabian, Iu. Skorodumina, G. D. Smith, D. Sokhan, N. Sparveris, S. Stepanyan, I. I. Strakovsky, S. Strauch, M. Taiuti, Ye Tian, B. Torayev, M. Ungaro, H. Voskanyan, E. Voutier, N. K. Walford, X. Wei, N. Zachariou, J. Zhang

Measurements of the linearly-polarized photon beam asymmetry $\Sigma$ for photoproduction from the proton of $\eta$ and $\eta^\prime$ mesons are reported. A linearly-polarized tagged photon beam produced by coherent bremsstrahlung was incident on a cryogenic hydrogen target within the CEBAF Large Acceptance Spectrometer. Results are presented for the $\gamma p \to \eta p$ reaction for incident photon energies from 1. Read More

Absorption imaging of ultracold atoms is the foundation for quantitative extraction of information from experiments with ultracold atoms. Due to the limited exposure time available in these systems, the signal-to-noise ratio is largest for high intensity absorption imaging where the intensity of the imaging light is on the order of the saturation intensity. In this case, the absolute value of the intensity of the imaging light enters as an additional parameter making it more sensitive to systematic errors. Read More

We show that every subset of vertices of a directed graph E gives a Morita equivalence between a subalgebra and an ideal of the associated Leavitt path algebra. We use this observation to prove an algebraic version of a theorem of Crisp and Gow: certain subgraphs of E can be contracted to a new graph G such that the Leavitt path algebras of E and G are Morita equivalent. We provide examples to illustrate how desingularising a graph, and in- or out-delaying of a graph, all fit into this setting. Read More

Optical control and manipulation of cold atoms has become an important topic in condensed matter. Widely employed are optical lattice shaking experiments which allow the introduction of artificial gauge fields, the design of topological bandstructures, and more general probing of quantum critical phenomena. Here we develop new numerical methods to simulate these periodically driven systems by implementing lattice shaking directly. Read More

2016Nov
Authors: P. E. Bosted1, A. Kim2, K. P. Adhikari3, D. Adikaram4, Z. Akbar5, M. J. Amaryan6, S. Anefalos Pereira7, H. Avakian8, R. A. Badui9, J. Ball10, I. Balossino11, M. Battaglieri12, I. Bedlinskiy13, A. S. Biselli14, S. Boiarinov15, W. J. Briscoe16, W. K. Brooks17, S. Bültmann18, V. D. Burkert19, T. Cao20, D. S. Carman21, A. Celentano22, S. Chandavar23, G. Charles24, T. Chetry25, G. Ciullo26, L. Clark27, L. Colaneri28, P. L. Cole29, M. Contalbrigo30, O. Cortes31, V. Crede32, A. D'Angelo33, N. Dashyan34, R. De Vita35, E. De Sanctis36, A. Deur37, C. Djalali38, R. Dupre39, H. Egiyan40, A. El Alaoui41, L. El Fassi42, L. Elouadrhiri43, P. Eugenio44, E. Fanchini45, G. Fedotov46, S. Fegan47, R. Fersch48, A. Filippi49, J. A. Fleming50, T. A. Forest51, A. Fradi52, Y. Ghandilyan53, G. P. Gilfoyle54, F. X. Girod55, D. I. Glazier56, W. Gohn57, E. Golovatch58, R. W. Gothe59, K. A. Griffioen60, M. Guidal61, N. Guler62, H. Hakobyan63, L. Guo64, K. Hafidi65, H. Hakobyan66, C. Hanretty67, N. Harrison68, M. Hattawy69, D. Heddle70, K. Hicks71, G. Hollis72, M. Holtrop73, S. M. Hughes74, D. G. Ireland75, E. L. Isupov76, D. Jenkins77, H. Jiang78, H. S. Jo79, K. Joo80, D. Keller81, G. Khachatryan82, M. Khandaker83, W. Kim84, A. Klei85, F. J. Klein86, S. Koirala87, V. Kubarovsky88, S. E. Kuhn89, L. Lanza90, P. Lenisa91, K. Livingston92, H. Y. Lu93, I. J. D. MacGregor94, N. Markov95, M. Mayer96, M. E. McCracken97, B. McKinnon98, T. Mineeva99, M. Mirazita100, V. I. Mokeev101, R. A. Montgomery102, A Movsisyan103, C. Munoz Camacho104, G. Murdoch105, P. Nadel-Turonski106, A. Ni107, S. Niccolai108, G. Niculescu109, M. Osipenko110, A. I. Ostrovidov111, M. Paolone112, R. Paremuzyan113, K. Park114, E. Pasyuk115, W. Phelps116, S. Pisano117, O. Pogorelko118, J. W. Price119, Y. Prok120, D. Protopopescu121, A. J. R. Puckett122, B. A. Raue123, M. Ripani124, A. Rizzo125, G. Rosner126, P. Rossi127, P. Roy128, F. Sabatié129, M. S. Saini130, R. A. Schumacher131, E. Seder132, Y. G. Sharabian133, Iu. Skorodumina134, G. D. Smith135, D. Sokhan136, N. Sparveris137, I. Stankovic138, S. Stepanyan139, P. Stoler140, I. I. Strakovsky141, S. Strauch142, M. Taiuti143, Ye Tian144, B. Torayev145, M. Ungaro146, H. Voskanyan147, E. Voutier148, N. K. Walford149, D. P. Watts150, X. Wei151, L. B. Weinstein152, N. Zachariou153, J. Zhang154, Z. W. Zhao155, I. Zonta156
Affiliations: 1The CLAS Collaboration, 2The CLAS Collaboration, 3The CLAS Collaboration, 4The CLAS Collaboration, 5The CLAS Collaboration, 6The CLAS Collaboration, 7The CLAS Collaboration, 8The CLAS Collaboration, 9The CLAS Collaboration, 10The CLAS Collaboration, 11The CLAS Collaboration, 12The CLAS Collaboration, 13The CLAS Collaboration, 14The CLAS Collaboration, 15The CLAS Collaboration, 16The CLAS Collaboration, 17The CLAS Collaboration, 18The CLAS Collaboration, 19The CLAS Collaboration, 20The CLAS Collaboration, 21The CLAS Collaboration, 22The CLAS Collaboration, 23The CLAS Collaboration, 24The CLAS Collaboration, 25The CLAS Collaboration, 26The CLAS Collaboration, 27The CLAS Collaboration, 28The CLAS Collaboration, 29The CLAS Collaboration, 30The CLAS Collaboration, 31The CLAS Collaboration, 32The CLAS Collaboration, 33The CLAS Collaboration, 34The CLAS Collaboration, 35The CLAS Collaboration, 36The CLAS Collaboration, 37The CLAS Collaboration, 38The CLAS Collaboration, 39The CLAS Collaboration, 40The CLAS Collaboration, 41The CLAS Collaboration, 42The CLAS Collaboration, 43The CLAS Collaboration, 44The CLAS Collaboration, 45The CLAS Collaboration, 46The CLAS Collaboration, 47The CLAS Collaboration, 48The CLAS Collaboration, 49The CLAS Collaboration, 50The CLAS Collaboration, 51The CLAS Collaboration, 52The CLAS Collaboration, 53The CLAS Collaboration, 54The CLAS Collaboration, 55The CLAS Collaboration, 56The CLAS Collaboration, 57The CLAS Collaboration, 58The CLAS Collaboration, 59The CLAS Collaboration, 60The CLAS Collaboration, 61The CLAS Collaboration, 62The CLAS Collaboration, 63The CLAS Collaboration, 64The CLAS Collaboration, 65The CLAS Collaboration, 66The CLAS Collaboration, 67The CLAS Collaboration, 68The CLAS Collaboration, 69The CLAS Collaboration, 70The CLAS Collaboration, 71The CLAS Collaboration, 72The CLAS Collaboration, 73The CLAS Collaboration, 74The CLAS Collaboration, 75The CLAS Collaboration, 76The CLAS Collaboration, 77The CLAS Collaboration, 78The CLAS Collaboration, 79The CLAS Collaboration, 80The CLAS Collaboration, 81The CLAS Collaboration, 82The CLAS Collaboration, 83The CLAS Collaboration, 84The CLAS Collaboration, 85The CLAS Collaboration, 86The CLAS Collaboration, 87The CLAS Collaboration, 88The CLAS Collaboration, 89The CLAS Collaboration, 90The CLAS Collaboration, 91The CLAS Collaboration, 92The CLAS Collaboration, 93The CLAS Collaboration, 94The CLAS Collaboration, 95The CLAS Collaboration, 96The CLAS Collaboration, 97The CLAS Collaboration, 98The CLAS Collaboration, 99The CLAS Collaboration, 100The CLAS Collaboration, 101The CLAS Collaboration, 102The CLAS Collaboration, 103The CLAS Collaboration, 104The CLAS Collaboration, 105The CLAS Collaboration, 106The CLAS Collaboration, 107The CLAS Collaboration, 108The CLAS Collaboration, 109The CLAS Collaboration, 110The CLAS Collaboration, 111The CLAS Collaboration, 112The CLAS Collaboration, 113The CLAS Collaboration, 114The CLAS Collaboration, 115The CLAS Collaboration, 116The CLAS Collaboration, 117The CLAS Collaboration, 118The CLAS Collaboration, 119The CLAS Collaboration, 120The CLAS Collaboration, 121The CLAS Collaboration, 122The CLAS Collaboration, 123The CLAS Collaboration, 124The CLAS Collaboration, 125The CLAS Collaboration, 126The CLAS Collaboration, 127The CLAS Collaboration, 128The CLAS Collaboration, 129The CLAS Collaboration, 130The CLAS Collaboration, 131The CLAS Collaboration, 132The CLAS Collaboration, 133The CLAS Collaboration, 134The CLAS Collaboration, 135The CLAS Collaboration, 136The CLAS Collaboration, 137The CLAS Collaboration, 138The CLAS Collaboration, 139The CLAS Collaboration, 140The CLAS Collaboration, 141The CLAS Collaboration, 142The CLAS Collaboration, 143The CLAS Collaboration, 144The CLAS Collaboration, 145The CLAS Collaboration, 146The CLAS Collaboration, 147The CLAS Collaboration, 148The CLAS Collaboration, 149The CLAS Collaboration, 150The CLAS Collaboration, 151The CLAS Collaboration, 152The CLAS Collaboration, 153The CLAS Collaboration, 154The CLAS Collaboration, 155The CLAS Collaboration, 156The CLAS Collaboration

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive $\pi^0$ electroproduction reaction $\gamma^* p \to p \pi^0$, expanding an analysis of the $\gamma^* p \to n \pi^+$ reaction from the same experiment. The results were obtained from scattering of 6 GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Lab. The kinematic range covered is $1. Read More

Open quantum systems usually reach a unique stationary state with ergodic dynamics. In other words, the ensemble averages and the time averages of the expectation values of open quantum systems are usually the same for all quantum trajectories. Although open quantum systems are in general ergodic, many classical stochastic processes are not. Read More

We study the domain walls which form when Bose condensates acquire a double-well dispersion. Experiments have observed such domain walls in condensates driven across a $\mathbb{Z}_2$ symmetry-breaking phase transition in a shaken optical lattice. We derive a generic model to describe the dispersion and to compute the wavefunctions and energies of the domain walls. Read More

Given an ample, Hausdorff groupoid $\mathcal{G}$, and a unital commutative ring $R$, we consider the Steinberg algebra $A_R(\mathcal {G})$. First we prove a uniqueness theorem for this algebra and then, when $\mathcal{G}$ is graded by a cocycle, we study graded ideals in $A_R(\mathcal {G})$. Applications are given for two classes of ample groupoids, namely those coming from actions of groups on graphs, and also to groupoids defined in terms of Boolean dynamical systems. Read More

There are a number of different strategies to measure the phase shift between two pathways of light more efficiently than suggested by the standard quantum limit. One way is to use highly entangled photons. Another way is to expose photons to a non-linear or interacting Hamiltonian. Read More

2016Jul
Authors: P. E. Bosted1, M. J. Amaryan2, S. Anefalos Pereira3, H. Avakian4, R. A. Badui5, J. Ball6, N. A. Baltzell7, M. Battaglieri8, V. Batourine9, I. Bedlinskiy10, A. S. Biselli11, W. J. Briscoe12, S. Bültmann13, V. D. Burkert14, D. S. Carman15, A. Celentano16, S. Chandavar17, G. Charles18, L. Clark19, L. Colaneri20, P. L. Cole21, M. Contalbrigo22, V. Crede23, A. D'Angelo24, R. De Vita25, A. Deur26, E. De Sanctis27, C. Djalali28, R. Dupre29, H. Egiyan30, A. El Alaoui31, L. El Fassi32, L. Elouadrhiri33, P. Eugenio34, E. Fanchini35, G. Fedotov36, A. Filippi37, J. A. Fleming38, T. Forest39, A. Fradi40, N. Gevorgyan41, G. P. Gilfoyle42, F. X. Girod43, C. Gleason44, W. Gohn45, E. Golovatch46, R. W. Gothe47, K. A. Griffioen48, M. Guidal49, H. Hakobyan50, M. Hattawy51, K. Hicks52, M. Holtrop53, S. M. Hughes54, Y. Ilieva55, D. G. Ireland56, B. S. Ishkhanov57, E. L. Isupov58, H. Jiang59, H. S. Jo60, K. Joo61, S. Joosten62, G. Khachatryan63, M. Khandaker64, A. Kim65, W. Kim66, F. J. Klein67, S. Koirala68, V. Kubarovsky69, S. E. Kuhn70, L. Lanza71, L. A. Net72, P. Lenisa73, K. Livingston74, I. J. D. MacGregor75, M. E. McCracken76, B. McKinnon77, C. A. Meyer78, M. Mirazita79, V. I. Mokeev80, R. A. Montgomery81, E. Munevar82, C. Munoz Camacho83, G. Murdoch84, P. Nadel-Turonski85, S. Niccolai86, M. Osipenko87, A. I. Ostrovidov88, K. Park89, E. Pasyuk90, P. Peng91, W. Phelps92, S. Pisano93, O. Pogorelko94, J. W. Price95, Y. Prok96, D. Protopopescu97, B. A. Raue98, M. Ripani99, G. Rosner100, P. Rossi101, R. A. Schumacher102, Iu. Skorodumina103, G. D. Smith104, D. Sokhan105, N. Sparveris106, I. Stankovic107, I. I. Strakovsky108, S. Strauch109, M. Taiuti110, B. Torayev111, M. Ungaro112, H. Voskanyan113, E. Voutier114, X. Wei115, L. B. Weinstein116, J. Zhang117, I. Zonta118
Affiliations: 1CLAS Collaboration, 2CLAS Collaboration, 3CLAS Collaboration, 4CLAS Collaboration, 5CLAS Collaboration, 6CLAS Collaboration, 7CLAS Collaboration, 8CLAS Collaboration, 9CLAS Collaboration, 10CLAS Collaboration, 11CLAS Collaboration, 12CLAS Collaboration, 13CLAS Collaboration, 14CLAS Collaboration, 15CLAS Collaboration, 16CLAS Collaboration, 17CLAS Collaboration, 18CLAS Collaboration, 19CLAS Collaboration, 20CLAS Collaboration, 21CLAS Collaboration, 22CLAS Collaboration, 23CLAS Collaboration, 24CLAS Collaboration, 25CLAS Collaboration, 26CLAS Collaboration, 27CLAS Collaboration, 28CLAS Collaboration, 29CLAS Collaboration, 30CLAS Collaboration, 31CLAS Collaboration, 32CLAS Collaboration, 33CLAS Collaboration, 34CLAS Collaboration, 35CLAS Collaboration, 36CLAS Collaboration, 37CLAS Collaboration, 38CLAS Collaboration, 39CLAS Collaboration, 40CLAS Collaboration, 41CLAS Collaboration, 42CLAS Collaboration, 43CLAS Collaboration, 44CLAS Collaboration, 45CLAS Collaboration, 46CLAS Collaboration, 47CLAS Collaboration, 48CLAS Collaboration, 49CLAS Collaboration, 50CLAS Collaboration, 51CLAS Collaboration, 52CLAS Collaboration, 53CLAS Collaboration, 54CLAS Collaboration, 55CLAS Collaboration, 56CLAS Collaboration, 57CLAS Collaboration, 58CLAS Collaboration, 59CLAS Collaboration, 60CLAS Collaboration, 61CLAS Collaboration, 62CLAS Collaboration, 63CLAS Collaboration, 64CLAS Collaboration, 65CLAS Collaboration, 66CLAS Collaboration, 67CLAS Collaboration, 68CLAS Collaboration, 69CLAS Collaboration, 70CLAS Collaboration, 71CLAS Collaboration, 72CLAS Collaboration, 73CLAS Collaboration, 74CLAS Collaboration, 75CLAS Collaboration, 76CLAS Collaboration, 77CLAS Collaboration, 78CLAS Collaboration, 79CLAS Collaboration, 80CLAS Collaboration, 81CLAS Collaboration, 82CLAS Collaboration, 83CLAS Collaboration, 84CLAS Collaboration, 85CLAS Collaboration, 86CLAS Collaboration, 87CLAS Collaboration, 88CLAS Collaboration, 89CLAS Collaboration, 90CLAS Collaboration, 91CLAS Collaboration, 92CLAS Collaboration, 93CLAS Collaboration, 94CLAS Collaboration, 95CLAS Collaboration, 96CLAS Collaboration, 97CLAS Collaboration, 98CLAS Collaboration, 99CLAS Collaboration, 100CLAS Collaboration, 101CLAS Collaboration, 102CLAS Collaboration, 103CLAS Collaboration, 104CLAS Collaboration, 105CLAS Collaboration, 106CLAS Collaboration, 107CLAS Collaboration, 108CLAS Collaboration, 109CLAS Collaboration, 110CLAS Collaboration, 111CLAS Collaboration, 112CLAS Collaboration, 113CLAS Collaboration, 114CLAS Collaboration, 115CLAS Collaboration, 116CLAS Collaboration, 117CLAS Collaboration, 118CLAS Collaboration

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive $\pi^+$ electroproduction reaction $\gamma^* p \to n \pi^+$. The results were obtained from scattering of 6 GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Lab. The kinematic range covered is $1. Read More

2016Jul
Authors: X. Zheng1, K. P. Adhikari2, P. Bosted3, A. Deur4, V. Drozdov5, L. El Fassi6, Hyekoo Kang7, K. Kovacs8, S. Kuhn9, E. Long10, S. K. Phillips11, M. Ripani12, K. Slifer13, L. C. Smith14, D. Adikaram15, Z. Akbar16, M. J. Amaryan17, S. Anefalos Pereira18, G. Asryan19, H. Avakian20, R. A. Badui21, J. Ball22, N. A. Baltzell23, M. Battaglieri24, V. Batourine25, I. Bedlinskiy26, A. S. Biselli27, W. J. Briscoe28, S. Bültmann29, V. D. Burkert30, D. S. Carman31, A. Celentano32, S. Chandavar33, G. Charles34, J. -P. Chen35, T. Chetry36, Seonho Choi37, G. Ciullo38, L. Clark39, L. Colaneri40, P. L. Cole41, N. Compton42, M. Contalbrigo43, V. Crede44, A. D'Angelo45, N. Dashyan46, R. De Vita47, E. De Sanctis48, C. Djalali49, G. E. Dodge50, R. Dupre51, H. Egiyan52, A. El Alaoui53, L. Elouadrhiri54, P. Eugenio55, E. Fanchini56, G. Fedotov57, R. Fersch58, A. Filippi59, J. A. Fleming60, N. Gevorgyan61, Y. Ghandilyan62, G. P. Gilfoyle63, K. L. Giovanetti64, F. X. Girod65, C. Gleason66, E. Golovach67, R. W. Gothe68, K. A. Griffioen69, M. Guidal70, N. Guler71, L. Guo72, C. Hanretty73, N. Harrison74, M. Hattawy75, K. Hicks76, M. Holtrop77, S. M. Hughes78, Y. Ilieva79, D. G. Ireland80, B. S. Ishkhanov81, E. L. Isupov82, D. Jenkins83, H. Jiang84, H. S. Jo85, S. Joosten86, D. Keller87, G. Khachatryan88, M. Khandaker89, A. Kim90, W. Kim91, F. J. Klein92, V. Kubarovsky93, L. Lanza94, P. Lenisa95, K. Livingston96, I . J . D. MacGregor97, N. Markov98, B. McKinnon99, M. Mirazita100, V. Mokeev101, A. Movsisyan102, E. Munevar103, C. Munoz Camacho104, G. Murdoch105, P. Nadel-Turonski106, L. A. Net107, A. Ni108, S. Niccolai109, G. Niculescu110, I. Niculescu111, M. Osipenko112, A. I. Ostrovidov113, M. Paolone114, R. Paremuzyan115, K. Park116, E. Pasyuk117, P. Peng118, S. Pisano119, O. Pogorelko120, J. W. Price121, A. J. R. Puckett122, B. A. Raue123, A. Rizzo124, G. Rosner125, P. Rossi126, P. Roy127, F. Sabatié128, C. Salgado129, R. A. Schumacher130, Y. G. Sharabian131, Iu. Skorodumina132, G. D. Smith133, D. Sokhan134, N. Sparveris135, I. Stankovic136, I. I. Strakovsky137, S. Strauch138, M. Taiuti139, Ye Tian140, M. Ungaro141, H. Voskanyan142, E. Voutier143, N. K. Walford144, D. P. Watts145, X. Wei146, L. B. Weinstein147, M. H. Wood148, N. Zachariou149, J. Zhang150
Affiliations: 1The CLAS Collaboration, 2The CLAS Collaboration, 3The CLAS Collaboration, 4The CLAS Collaboration, 5The CLAS Collaboration, 6The CLAS Collaboration, 7The CLAS Collaboration, 8The CLAS Collaboration, 9The CLAS Collaboration, 10The CLAS Collaboration, 11The CLAS Collaboration, 12The CLAS Collaboration, 13The CLAS Collaboration, 14The CLAS Collaboration, 15The CLAS Collaboration, 16The CLAS Collaboration, 17The CLAS Collaboration, 18The CLAS Collaboration, 19The CLAS Collaboration, 20The CLAS Collaboration, 21The CLAS Collaboration, 22The CLAS Collaboration, 23The CLAS Collaboration, 24The CLAS Collaboration, 25The CLAS Collaboration, 26The CLAS Collaboration, 27The CLAS Collaboration, 28The CLAS Collaboration, 29The CLAS Collaboration, 30The CLAS Collaboration, 31The CLAS Collaboration, 32The CLAS Collaboration, 33The CLAS Collaboration, 34The CLAS Collaboration, 35The CLAS Collaboration, 36The CLAS Collaboration, 37The CLAS Collaboration, 38The CLAS Collaboration, 39The CLAS Collaboration, 40The CLAS Collaboration, 41The CLAS Collaboration, 42The CLAS Collaboration, 43The CLAS Collaboration, 44The CLAS Collaboration, 45The CLAS Collaboration, 46The CLAS Collaboration, 47The CLAS Collaboration, 48The CLAS Collaboration, 49The CLAS Collaboration, 50The CLAS Collaboration, 51The CLAS Collaboration, 52The CLAS Collaboration, 53The CLAS Collaboration, 54The CLAS Collaboration, 55The CLAS Collaboration, 56The CLAS Collaboration, 57The CLAS Collaboration, 58The CLAS Collaboration, 59The CLAS Collaboration, 60The CLAS Collaboration, 61The CLAS Collaboration, 62The CLAS Collaboration, 63The CLAS Collaboration, 64The CLAS Collaboration, 65The CLAS Collaboration, 66The CLAS Collaboration, 67The CLAS Collaboration, 68The CLAS Collaboration, 69The CLAS Collaboration, 70The CLAS Collaboration, 71The CLAS Collaboration, 72The CLAS Collaboration, 73The CLAS Collaboration, 74The CLAS Collaboration, 75The CLAS Collaboration, 76The CLAS Collaboration, 77The CLAS Collaboration, 78The CLAS Collaboration, 79The CLAS Collaboration, 80The CLAS Collaboration, 81The CLAS Collaboration, 82The CLAS Collaboration, 83The CLAS Collaboration, 84The CLAS Collaboration, 85The CLAS Collaboration, 86The CLAS Collaboration, 87The CLAS Collaboration, 88The CLAS Collaboration, 89The CLAS Collaboration, 90The CLAS Collaboration, 91The CLAS Collaboration, 92The CLAS Collaboration, 93The CLAS Collaboration, 94The CLAS Collaboration, 95The CLAS Collaboration, 96The CLAS Collaboration, 97The CLAS Collaboration, 98The CLAS Collaboration, 99The CLAS Collaboration, 100The CLAS Collaboration, 101The CLAS Collaboration, 102The CLAS Collaboration, 103The CLAS Collaboration, 104The CLAS Collaboration, 105The CLAS Collaboration, 106The CLAS Collaboration, 107The CLAS Collaboration, 108The CLAS Collaboration, 109The CLAS Collaboration, 110The CLAS Collaboration, 111The CLAS Collaboration, 112The CLAS Collaboration, 113The CLAS Collaboration, 114The CLAS Collaboration, 115The CLAS Collaboration, 116The CLAS Collaboration, 117The CLAS Collaboration, 118The CLAS Collaboration, 119The CLAS Collaboration, 120The CLAS Collaboration, 121The CLAS Collaboration, 122The CLAS Collaboration, 123The CLAS Collaboration, 124The CLAS Collaboration, 125The CLAS Collaboration, 126The CLAS Collaboration, 127The CLAS Collaboration, 128The CLAS Collaboration, 129The CLAS Collaboration, 130The CLAS Collaboration, 131The CLAS Collaboration, 132The CLAS Collaboration, 133The CLAS Collaboration, 134The CLAS Collaboration, 135The CLAS Collaboration, 136The CLAS Collaboration, 137The CLAS Collaboration, 138The CLAS Collaboration, 139The CLAS Collaboration, 140The CLAS Collaboration, 141The CLAS Collaboration, 142The CLAS Collaboration, 143The CLAS Collaboration, 144The CLAS Collaboration, 145The CLAS Collaboration, 146The CLAS Collaboration, 147The CLAS Collaboration, 148The CLAS Collaboration, 149The CLAS Collaboration, 150The CLAS Collaboration

We report measurements of target- and double-spin asymmetries for the exclusive channel $\vec e\vec p\to e\pi^+ (n)$ in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH$_3$ target and a longitudinally polarized electron beam with energies 1.1, 1. Read More

Ramsey theory is an active research area in combinatorics whose central theme is the emergence of order in large disordered structures, with Ramsey numbers marking the threshold at which this order first appears. For generalized Ramsey numbers $r(G,H)$, the emergent order is characterized by graphs $G$ and $H$. In this paper we: (i) present a quantum algorithm for computing generalized Ramsey numbers by reformulating the computation as a combinatorial optimization problem which is solved using adiabatic quantum optimization; and (ii) determine the Ramsey numbers $r(\mathcal{T}_{m},\mathcal{T}_{n})$ for trees of order $m,n = 6,7,8$, most of which were previously unknown. Read More

The use of phase plates in the back focal plane of a microscope is a well established technique in optical microscopy to increase the contrast of weakly interacting samples and is gaining interest in electron microscopy as well. In this paper we study the spiral phase plate (SPP), also called helical, vortex, or two-dimensional Hilbert phase plate, that adds an angularly dependent phase of the form $e^{i\ell\phi}$ to the exit wave in Fourier space. In the limit of large collection angles, we analytically calculate that the average of a pair of $\ell=\pm1$ SPP images is directly proportional to the gradient squared of the exit wave, explaining the edge contrast previously seen in optical SPP work. Read More

The dynamics of many-body systems spanning condensed matter, cosmology, and beyond is hypothesized to be universal when the systems cross continuous phase transitions. The universal dynamics is expected to satisfy a scaling symmetry of space and time with the crossing rate, inspired by the Kibble-Zurek mechanism. We test this symmetry based on Bose condensates in a shaken optical lattice. Read More

2016Apr
Authors: P. E. Bosted1, A. S. Biselli2, S. Careccia3, G. Dodge4, R. Fersch5, S. E. Kuhn6, J. Pierce7, Y. Prok8, X. Zheng9, K. P. Adhikari10, D. Adikaram11, Z. Akbar12, M. J. Amaryan13, S. Anefalos Pereira14, G. Asryan15, H. Avakian16, R. A. Badui17, J. Ball18, N. A. Baltzell19, M. Battaglieri20, V. Batourine21, I. Bedlinskiy22, S. Boiarinov23, W. J. Briscoe24, S. Bültmann25, V. D. Burkert26, T. Cao27, D. S. Carman28, A. Celentano29, S. Chandavar30, G. Charles31, T. Chetry32, G. Ciullo33, L. Clark34, L. Colaneri35, P. L. Cole36, M. Contalbrigo37, O. Cortes38, V. Crede39, A. D'Angelo40, N. Dashyan41, R. De Vita42, A. Deur43, C. Djalali44, R. Dupre45, H. Egiyan46, A. El Alaoui47, L. El Fassi48, P. Eugenio49, E. Fanchini50, G. Fedotov51, A. Filippi52, J. A. Fleming53, T. A. Forest54, A. Fradi55, M. Garçon56, N. Gevorgyan57, Y. Ghandilyan58, G. P. Gilfoyle59, K. L. Giovanetti60, F. X. Girod61, C. Gleason62, W. Gohn63, E. Golovatch64, R. W. Gothe65, K. A. Griffioen66, N. Guler67, L. Guo68, K. Hafidi69, C. Hanretty70, N. Harrison71, M. Hattawy72, D. Heddle73, K. Hicks74, M. Holtrop75, S. M. Hughes76, Y. Ilieva77, D. G. Ireland78, B. S. Ishkhanov79, E. L. Isupov80, D. Jenkins81, H. Jiang82, H. S. Jo83, K. Joo84, S. Joosten85, D. Keller86, M. Khandaker87, W. Kim88, A. Klein89, F. J. Klein90, V. Kubarovsky91, S. V. Kuleshov92, L. Lanza93, P. Lenisa94, K. Livingston95, H. Y. Lu96, I . J . D. MacGregor97, N. Markov98, M. E. McCracken99, B. McKinnon100, C. A. Meyer101, R. Minehart102, M. Mirazita103, V. Mokeev104, A Movsisyan105, E. Munevar106, C. Munoz Camacho107, P. Nadel-Turonski108, L. A. Net109, A. Ni110, S. Niccolai111, G. Niculescu112, I. Niculescu113, M. Osipenko114, A. I. Ostrovidov115, R. Paremuzyan116, K. Park117, E. Pasyuk118, P. Peng119, W. Phelps120, S. Pisano121, O. Pogorelko122, J. W. Price123, S. Procureur124, D. Protopopescu125, A. J. R. Puckett126, B. A. Raue127, M. Ripani128, A. Rizzo129, G. Rosner130, P. Rossi131, P. Roy132, F. Sabatié133, C. Salgado134, R. A. Schumacher135, E. Seder136, Y. G. Sharabian137, A. Simonyan138, Iu. Skorodumina139, G. D. Smith140, N. Sparveris141, Ivana Stankovic142, S. Stepanyan143, I. I. Strakovsky144, S. Strauch145, V. Sytnik146, M. Taiuti147, Ye Tian148, B. Torayev149, M. Ungaro150, H. Voskanyan151, E. Voutier152, N. K. Walford153, D. P. Watts154, X. Wei155, L. B. Weinstein156, M. H. Wood157, N. Zachariou158, L. Zana159, J. Zhang160, Z. W. Zhao161, I. Zonta162
Affiliations: 1CLAS Collaboration, 2CLAS Collaboration, 3CLAS Collaboration, 4CLAS Collaboration, 5CLAS Collaboration, 6CLAS Collaboration, 7CLAS Collaboration, 8CLAS Collaboration, 9CLAS Collaboration, 10CLAS Collaboration, 11CLAS Collaboration, 12CLAS Collaboration, 13CLAS Collaboration, 14CLAS Collaboration, 15CLAS Collaboration, 16CLAS Collaboration, 17CLAS Collaboration, 18CLAS Collaboration, 19CLAS Collaboration, 20CLAS Collaboration, 21CLAS Collaboration, 22CLAS Collaboration, 23CLAS Collaboration, 24CLAS Collaboration, 25CLAS Collaboration, 26CLAS Collaboration, 27CLAS Collaboration, 28CLAS Collaboration, 29CLAS Collaboration, 30CLAS Collaboration, 31CLAS Collaboration, 32CLAS Collaboration, 33CLAS Collaboration, 34CLAS Collaboration, 35CLAS Collaboration, 36CLAS Collaboration, 37CLAS Collaboration, 38CLAS Collaboration, 39CLAS Collaboration, 40CLAS Collaboration, 41CLAS Collaboration, 42CLAS Collaboration, 43CLAS Collaboration, 44CLAS Collaboration, 45CLAS Collaboration, 46CLAS Collaboration, 47CLAS Collaboration, 48CLAS Collaboration, 49CLAS Collaboration, 50CLAS Collaboration, 51CLAS Collaboration, 52CLAS Collaboration, 53CLAS Collaboration, 54CLAS Collaboration, 55CLAS Collaboration, 56CLAS Collaboration, 57CLAS Collaboration, 58CLAS Collaboration, 59CLAS Collaboration, 60CLAS Collaboration, 61CLAS Collaboration, 62CLAS Collaboration, 63CLAS Collaboration, 64CLAS Collaboration, 65CLAS Collaboration, 66CLAS Collaboration, 67CLAS Collaboration, 68CLAS Collaboration, 69CLAS Collaboration, 70CLAS Collaboration, 71CLAS Collaboration, 72CLAS Collaboration, 73CLAS Collaboration, 74CLAS Collaboration, 75CLAS Collaboration, 76CLAS Collaboration, 77CLAS Collaboration, 78CLAS Collaboration, 79CLAS Collaboration, 80CLAS Collaboration, 81CLAS Collaboration, 82CLAS Collaboration, 83CLAS Collaboration, 84CLAS Collaboration, 85CLAS Collaboration, 86CLAS Collaboration, 87CLAS Collaboration, 88CLAS Collaboration, 89CLAS Collaboration, 90CLAS Collaboration, 91CLAS Collaboration, 92CLAS Collaboration, 93CLAS Collaboration, 94CLAS Collaboration, 95CLAS Collaboration, 96CLAS Collaboration, 97CLAS Collaboration, 98CLAS Collaboration, 99CLAS Collaboration, 100CLAS Collaboration, 101CLAS Collaboration, 102CLAS Collaboration, 103CLAS Collaboration, 104CLAS Collaboration, 105CLAS Collaboration, 106CLAS Collaboration, 107CLAS Collaboration, 108CLAS Collaboration, 109CLAS Collaboration, 110CLAS Collaboration, 111CLAS Collaboration, 112CLAS Collaboration, 113CLAS Collaboration, 114CLAS Collaboration, 115CLAS Collaboration, 116CLAS Collaboration, 117CLAS Collaboration, 118CLAS Collaboration, 119CLAS Collaboration, 120CLAS Collaboration, 121CLAS Collaboration, 122CLAS Collaboration, 123CLAS Collaboration, 124CLAS Collaboration, 125CLAS Collaboration, 126CLAS Collaboration, 127CLAS Collaboration, 128CLAS Collaboration, 129CLAS Collaboration, 130CLAS Collaboration, 131CLAS Collaboration, 132CLAS Collaboration, 133CLAS Collaboration, 134CLAS Collaboration, 135CLAS Collaboration, 136CLAS Collaboration, 137CLAS Collaboration, 138CLAS Collaboration, 139CLAS Collaboration, 140CLAS Collaboration, 141CLAS Collaboration, 142CLAS Collaboration, 143CLAS Collaboration, 144CLAS Collaboration, 145CLAS Collaboration, 146CLAS Collaboration, 147CLAS Collaboration, 148CLAS Collaboration, 149CLAS Collaboration, 150CLAS Collaboration, 151CLAS Collaboration, 152CLAS Collaboration, 153CLAS Collaboration, 154CLAS Collaboration, 155CLAS Collaboration, 156CLAS Collaboration, 157CLAS Collaboration, 158CLAS Collaboration, 159CLAS Collaboration, 160CLAS Collaboration, 161CLAS Collaboration, 162CLAS Collaboration

Beam-target double spin asymmetries and target single-spin asymmetries in exclusive $\pi^+$ and $\pi^-$ electroproduction were obtained from scattering of 1.6 to 5.7 GeV longitudinally polarized electrons from longitudinally polarized protons (for $\pi^+$) and deuterons (for $\pi^-$) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Read More

Given an arbitrary graph, we describe the center of its Leavitt path algebra over a commutative unital ring. Our proof uses the Steinberg algebra model of the Leavitt path algebra. A key ingredient is a characterization of compact open invariant subsets of the unit space of the graph groupoid in terms of the underlying graph: an open invariant subset is compact if and only if its associated hereditary and saturated set of vertices satisfies Condition (F). Read More

In this article, we introduce Cohn path algebras of higher-rank graphs. We prove that for a higher-rank graph $\Lambda $, there exists a higher-rank graph $T\Lambda $ such that the Cohn path algebra of $\Lambda $ is isomorphic to the Kumjian-Pask algebra of $T\Lambda $. We then use this isomorphism and properties of Kumjian-Pask algebras to study Cohn path algebras. Read More

2016Mar
Authors: D. Rimal, D. Adikaram, B. A. Raue, L. B. Weinstein, J. Arrington, W. K. Brooks, M. Ungaro, K. P. Adhikari, Z. Akbar, S. Anefalos Pereira, R. A. Badui, J. Ball, N. A. Baltzell, M. Battaglieri, V. Batourine, I. Bedlinskiy, R. P. Bennett, A. S. Biselli, S. Boiarinov, W. J. Briscoe, S. Bültmann, D. S. Carman, A. Celentano, T. Chetry, G. Ciullo, L. Clark, L. Colaneri, P. L. Cole, N. Compton, M. Contalbrigo, O. Cortes, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, A. Deur, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, P. Eugenio, G. Fedotov, R. Fersch, A. Filippi, J. A. Fleming, T. A. Forest, A. Fradi, N. Gevorgyan, Y. Ghandilyan, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, C. Gleason, W. Gohn, E. Golovatch, R. W. Gothe, K. A. Griffioen, L. Guo, K. Hafidi, C. Hanretty, N. Harrison, M. Hattawy, D. Heddle, K. Hicks, M. Holtrop, S. M. Hughes, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, D. Jenkins, H. Jiang, S. Joosten, D. Keller, P. Khetarpal, G. Khachatryan, M. Khandaker, W. Kim, A. Klein, F. J. Klein, V. Kubarovsky, S. E. Kuhn, S. V. Kuleshov, L. Lanza, P. Lenisa, K. Livingston, H. Y. Lu, I . J . D. MacGregor, N. Markov, B. McKinnon, M. D. Mestayer, M. Mirazita, V. Mokeev, A Movsisyan, E. Munevar, C. Munoz Camacho, P. Nadel-Turonski, A. Ni, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, A. I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, E. Pasyuk, W. Phelps, S. Pisano, O. Pogorelko, J. W. Price, Y. Prok, D. Protopopescu, A. J. R. Puckett, A. Rizzo, G. Rosner, P. Rossi, P. Roy, F. Sabatié, C. Salgado, R. A. Schumacher, E. Seder, Y. G. Sharabian, Iu. Skorodumina, G. D. Smith, D. Sokhan, N. Sparveris, Ivana Stankovic, S. Stepanyan, S. Strauch, V. Sytnik, M. Taiuti, B. Torayev, H. Voskanyan, E. Voutier, N. K. Walford, D. P. Watts, X. Wei, M. H. Wood, N. Zachariou, L. Zana, J. Zhang, Z. W. Zhao, I. Zonta

[Background] The electromagnetic form factors of the proton measured by unpolarized and polarized electron scattering experiments show a significant disagreement that grows with the squared four momentum transfer ($Q^{2}$). Calculations have shown that the two measurements can be largely reconciled by accounting for the contributions of two-photon exchange (TPE). TPE effects are not typically included in the standard set of radiative corrections since theoretical calculations of the TPE effects are highly model dependent, and, until recently, no direct evidence of significant TPE effects has been observed. Read More

Given an arbitrary graph $E$ we investigate the relationship between $E$ and the groupoid $G_E$. We show that there is a lattice isomorphism between the lattice of pairs $(H, S)$, where $H$ is a hereditary and saturated set of vertices and $S$ is a set of breaking vertices {associated to $H $}, onto the lattice of open invariant subsets of $G_E^{(0)}$. We use this lattice isomorphism to characterize the decomposability of the Leavitt path algebra $L_K(E)$, where $K$ is a field. Read More

Electron vortex beams hold great promise for development in transmission electron microscopy, but have yet to be widely adopted. This is partly due to the complex set of interactions that occur between a beam carrying orbital angular momentum (OAM) and a sample. Herein, the system is simplified to focus on the interaction between geometrical symmetries, OAM and topology. Read More

Let $\Lambda$ be a row-finite higher-rank graph with no sources. We identify a maximal commutative subalgebra $\mathcal{M}$ inside the Kumjian-Pask algebra ${\rm KP}_R(\Lambda)$. We also prove a generalized Cuntz-Krieger uniqueness theorem for Kumjian-Pask algebras which says that a representation of ${\rm KP}_R(\Lambda)$ is injective if and only if it is injective on $\mathcal{M}$. Read More

We consider the ideal structure of Steinberg algebras over a commutative ring with identity. We focus on Hausdorff groupoids that are strongly effective in the sense that their reductions to closed subspaces of their unit spaces are all effective. For such a groupoid, we completely describe the ideal lattice of the associated Steinberg algebra over any commutative ring with identity. Read More

We extend the the definition of Kumjian-Pask algebras to include algebras associated to finitely aligned higher-rank graphs. We show that these Kumjian-Pask algebras are universally defined and have a graded uniqueness theorem. We also prove the Cuntz-Kreiger uniqueness theorem; to do this, we use a groupoid approach. Read More

In this paper, we use the non-linear dynamics of the individual quantum trajectories of an optical cavity inside an instantaneous quantum feedback loop to measure the phase shift between two pathways of light with an accuracy above the standard quantum limit. The feedback laser provides a reference frame and constantly increases the dependence of the state of the resonator on the unknown phase. Since our quantum metrology scheme can be implemented with current technology and does not require highly-efficient single photon detectors, it should be of practical interest until highly-entangled many-photon states become more readily available. Read More

The graph groupoids of directed graphs are topologically isomorphic if and only if there is a diagonal-preserving ring *-isomorphism between the Leavitt path algebras. Read More

We characterise quasidiagonality of the $C^*$-algebra of a cofinal $k$-graph in terms of an algebraic condition involving the coordinate matrices of the graph. This result covers all simple $k$-graph $C^*$-algebras. In the special case of cofinal $2$-graphs we further prove that AF-embeddability, quasidiagonality and stable finiteness of the $2$-graph algebra are all equivalent. Read More

Optical control of atomic interactions in a quantum gas is a long-sought goal of cold atom research. Previous experiments have been hindered by short lifetimes and parasitic deformation of the trap potential. Here, we develop and implement a generic scheme for optical control of Feshbach resonance in quantum gases, which yields long condensate lifetimes sufficient to study equilibrium and non-equilibrium physics with negligible parasitic dipole force. Read More

In this paper we explore the desirability of a transmission electron microscope in which the phase of the electron wave can be freely controlled. We discuss different existing methods to manipulate the phase of the electron wave and their limitations. We show how with the help of current techniques the electron wave can already be crafted into specific classes of waves each having their own peculiar properties. Read More

From a suitable groupoid G, we show how to construct an amenable principal groupoid whose C*-algebra is a Kirchberg algebra which is KK-equivalent to C*(G). Using this construction, we show by example that many UCT Kirchberg algebras can be realised as the C*-algebras of amenable principal groupoids. Read More

Spielberg has recently shown that Baumslag-Solitar groups associated to pairs of positive integers are quasi-lattice ordered in the sense of Nica. Thus they have tractable Toeplitz algebras. Each of these algebras carries a natural dynamics. Read More

This paper extends those of Glendinning and Sidorov [3] and of Hare and Sidorov [6] from the case of the doubling map to the more general $\beta$-transformation. Let $\beta \in (1,2)$ and consider the $\beta$-transformation $T_{\beta}(x)=\beta x \pmod 1$. Let $\mathcal{J}_{\beta} (a,b) := \{ x \in (0,1) : T_{\beta}^n(x) \notin (a,b) \text{ for all } n \geq 0 \}$. Read More

We investigate topological aspects of sub-nm electron vortex beams upon elastic propagation through atomic scattering potentials. Two main aspects can be distinguished: (i) Significantly reduced delocalization compared to a similar non-vortex beam if the beam centers on an atomic column and (ii) site symmetry dependent splitting of higher-order vortex beams. Furthermore, the results provide insight into the complex vortex line fabric within the elastically scattered wave containing characteristic vortex loops predominantly attached to atomic columns and characteristic twists of vortex lines around atomic columns. Read More

We present experimental evidence showing that an interacting Bose condensate in a shaken optical lattice develops a roton-maxon excitation spectrum, a feature normally associated with superfluid helium. The roton-maxon feature originates from the double-well dispersion in the shaken lattice, and can be controlled by both the atomic interaction and the lattice shaking amplitude. We determine the excitation spectrum using Bragg spectroscopy and measure the critical velocity by dragging a weak speckle potential through the condensate - both techniques are based on a digital micromirror device. Read More

Hidden Markov Models are widely used in classical computer science to model stochastic processes with a wide range of applications. This paper concerns the quantum analogues of these machines --- so-called Hidden Quantum Markov Models (HQMMs). Using the properties of Quantum Physics, HQMMs are able to generate more complex random output sequences than their classical counterparts, even when using the same number of internal states. Read More

We present new magnetic heat capacity and neutron scattering results for two magnetically frustrated molybdate pyrochlores: $S=1$ oxide Lu$_2$Mo$_2$O$_7$ and $S={\frac{1}{2}}$ oxynitride Lu$_2$Mo$_2$O$_5$N$_2$. Lu$_2$Mo$_2$O$_7$ undergoes a transition to an unconventional spin glass ground state at $T_f {\sim} 16$ K. However, the preparation of the corresponding oxynitride tunes the nature of the ground state from spin glass to quantum spin liquid. Read More

In TEM, a typical goal consists of making a small electron probe in the sample plane in order to obtain high spatial resolution in scanning transmission electron microscopy. In order to do so, the phase of the electron wave is corrected to resemble a spherical wave compensating for aberrations in the magnetic lenses. In this contribution we discuss the advantage of changing the phase of an electron wave in a specific way in order to obtain fundamentally different electron probes opening up new application in the (S)TEM. Read More

Electron vortex beams have been predicted to enable atomic scale magnetic information measurement, via transfer of orbital angular momentum. Research so far has focussed on developing production techniques and applications of these beams. However, methods to measure the outgoing orbital angular momentum distribution are also a crucial requirement towards this goal. Read More

Let $G$ be a Hausdorff, \'etale groupoid that is minimal and topologically principal. We show that $C^*_r(G)$ is purely infinite simple if and only if all the nonzero positive elements of $C_0(G^0)$ are infinite in $C_r^*(G)$. If $G$ is a Hausdorff, ample groupoid, then we show that $C^*_r(G)$ is purely infinite simple if and only if every nonzero projection in $C_0(G^0)$ is infinite in $C^*_r(G)$. Read More

We prove Cuntz-Krieger and graded uniqueness theorems for Steinberg algebras. We also show that a Steinberg algebra is basically simple if and only if its associated groupoid is both effective and minimal. Finally we use results of Steinberg to characterise the center of Steinberg algebras associated to minimal groupoids Read More

The recent demonstration of electron vortex beams has opened up the new possibility of studying orbital angular momentum (OAM) in the interaction between electron beams and matter. To this aim, methods to analyze the OAM of an electron beam are fundamentally important and a necessary next step. We demonstrate the measurement of electron beam OAM through a variety of techniques. Read More

Let $G$ and $H$ be Hausdorff ample groupoids and let $R$ be a commutative unital ring. We show that if $G$ and $H$ are equivalent in the sense of Muhly-Renault-Williams, then the associated Steinberg algebras of locally constant $R$-valued functions with compact support are Morita equivalent. We deduce that collapsing a ``collapsible subgraph" of a directed graph in the sense of Crisp and Gow does not change the Morita-equivalence class of the associated Leavitt path $R$-algebra, and therefore a number of graphical constructions which yield Morita equivalent $C^*$-algebras also yield Morita equivalent Leavitt path algebras. Read More

The vanadium oxyfluoride [NH4]2[C7H14N][V7O6F18] (DQVOF) is a geometrically frustrated magnetic bilayer material. The structure consists of S=1/2 kagome planes of V4+ d1 ions with S=1 V3+ d2 ions located between the kagome layers. Muon spin relaxation measurements demonstrate the absence of spin freezing down to 40 mK despite an energy scale of 60 K for antiferromagnetic exchange interactions. Read More

A model for a new electron vortex beam production method is proposed and experimentally demonstrated. The technique calls on the controlled manipulation of the degrees of freedom of the lens aberrations to achieve a helical phase front. These degrees of freedom are accessible by using the corrector lenses of a transmission electron microscope. Read More