Classical-to-quantum crossover in electron on-demand emission

Solid-state on-demand sources of coherent electrons offer new possibilities to explore and exploit the distinction between quantum and classical properties of individual particles. Here we investigate theoretically an emission mechanism that enables a crossover from stochastic semi-classical to Heisenberg-limited quantum wave-packets. The source is modelled by an energy level tunnel-coupled to an empty conduction band and driven up linearly in time; emission control is achieved by designing the energy dependence of the tunnel-coupling density and tuning the driving rate. Applying an exact solution to a generic example, we demonstrate the relevance of the proposed mechanism for experimentally demonstrated devices for few-electron quantum technologies.

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