Single-electron source: Adiabatic versus nonadiabatic emission

Abstract

We investigate adiabatic and nonadiabatic emission of single particles into an edge state using an analytically solvable dynamical scattering matrix model of an on-demand source. We compare adiabatic and nonadiabatic emissions by considering two geometries: a collider geometry where two emitters are coupled to two different edge states and a series geometry where two emitters are coupled to the same edge state. Most effects observed for adiabatic emitters also occur for nonadiabatic emitters. In particular this applies to effects arising due to the overlap of wave packets colliding at a quantum point contact. Specifically we compare the Pauli peak (the fermionic analog of the bosonic Hong-Ou-Mandel dip) for the adiabatic and nonadiabatic collider and find them to be similar. In contrast we find a striking difference between the two operating conditions in the series geometry in which particles are emitted into the same edge state. Whereas the squared average charge current can be nullified for both operating conditions, the heat current can be made to vanish only with adiabatic emitters.

Dephasing in single-electron generation due to environmental noise probed by Hong-Ou-Mandel interferometry

“…(23) and Eq. (24). Using |a + b| |a| + |b|, 0, and γ p 0, one can evaluate the amplitude of δn d (t) from…”

“…The experiments of on-demand electron generation in electronic transmission channels have stimulated the theoretical study on the quantum-mechanical nature of the single electrons which are generated in the one-dimensional channel [16][17][18][19][20][21][22][23][24][25][26][27][28][29]. * iyoda@noneq.c.u-tokyo.ac.jp…”

Fermi-sea correlations and a single-electron time-bin qubit

“…Importantly, for electrons emitted adiabatically, the excess energy (i.e., the energy counted from μ or, simply, heat) is proportional to the squared electrical current integrated over time, that is in accordance with the well-known Joule-Lentz law [39,46]. Therefore, heat carried by either a single-peak particle (upper panel in Fig.…”

“…If the voltage U (t) changes so slow that the crossing time (the time during which a broadened level crosses the Fermi level) is large compared to the dwell time [the time during which an electron escapes a capacitor, τ D = h/(T QPC ), where is the level spacing], then such a regime is called adiabatic [38,39]. In this regime at zero temperature the generated current, I (t) = e(−i/2π )S ∂S * /∂t [40][41][42], is expressed in terms of the scattering amplitude S(t) for electrons with energy μ propagating in the waveguide and passing by the capacitor.…”

Polarized heat current generated by quantum pumping in two-dimensional topological insulators

“…Interestingly, locally applied time-dependent voltages can lead to heat pumping mechanisms in quantum systems [9,31,[37][38][39][40][41][42]. The peculiar characteristic of heat pumps is that a direct heat current is generated by a purely ac drive which acts against some present thermal gradients.…”