Adiabatic quantum pumping in an Aharonov-Bohm loop and in a Si-like nanowire: Role of interference in real space and in momentum space

TL;DR

This paper investigates how interference effects in real and momentum space influence adiabatic quantum pumping in two 1D lattice models, highlighting the role of Aharonov-Bohm phases and band degeneracies.

Contribution

It introduces two models demonstrating the impact of interference on quantum pumping, emphasizing the control via Aharonov-Bohm phase and band structure effects.

Findings

AB phase controls pumped current in the Aharonov-Bohm loop

Interference between degenerate states affects pumping in the Si-like nanowire

Interference effects can be used to regulate quantum transport

Abstract

We study the consequences of interference effects on the current generated by adiabatic quantum pumping in two distinct one-dimensional (1D) lattice model. The first model contains an Aharonov-Bohm (AB) loop within a tight-binding chain of lattice sites. The static AB phase is shown to strongly affect interference between the two arms of the loop, serving as an on-off switch and regulator for the pumped current. The second model simulates pumping in semiconductors with indirect band-gaps, by utilizing a tight-binding chain with next-nearest-neighbor coupling. The model exhibits signatures of interference between degenerate conduction band states with different Fermi wavevectors.