Quantum effect of inductance on geometric Cooper-pair transport

Abstract

We introduce a model for a flux-assisted Cooper-pair pump, the sluice, which is used to study geometric charge transport. Our model allows for a nonvanishing loop inductance going beyond the usual treatment with an exact phase bias. We derive the device Hamiltonian and current operators for different elements of the system and calculate the pumped charge carried by the ground state in the adiabatic limit. We show that extending the model beyond the exact phase bias, has a weak but potentially non-negligible effect on the charge transport. This effect is observed to depend on the external flux bias. The adiabatic energy level and eigenstate structures are studied and the unusual features are explained. Finally, we discuss the requirements of adiabaticity.Comment: 13 pages, 6 figures, final versio

Coherent Cooper-pair pumping by magnetic flux control

“…A Cooper-pair pump 1 is a superconducting device that can be used to transport Cooper pairs by manipulating some of its parameters in a periodic fashion. Cooper-pair pumps have recently attracted considerable theoretical [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] and experimental [17][18][19][20][21][22] attention.…”