Quantum pumping in deformable quantum dots

TL;DR

This paper investigates how elastic deformations in quantum dots affect adiabatic charge pumping, revealing an unconventional phase relation caused by dynamical phase shifts from mechanical vibrations.

Contribution

It introduces a theoretical analysis of quantum pumping in deformable quantum dots, highlighting the impact of elastic deformations and phonon-induced phase shifts on current behavior.

Findings

Current shows an undefined parity with respect to phase  in deformable dots.

Dynamical phase shift _D arises from elastic deformations affecting the current-phase relation.

Mechanical resonance and quality factor Q influence the pumped current and phase behavior.

Abstract

The charge current pumped adiabatically through a deformable quantum dot is studied within the Green's function approach. Differently from the non-deformable case, the current shows an undefined parity with respect to the pumping phase \phi. The unconventional current-phase relation, analyzed in the weak pumping regime, is due to a dynamical phase shift \phi_D caused by the elastic deformations of the central region (classical phonons). The role of the quality factor Q of the oscillator, the effects induced by a mechanical resonance and the implications for current experiments on molecular systems are also discussed.