Charge decoherence in laterally coupled quantum dots due to electron-phonon interactions

TL;DR

This paper analyzes how electron-phonon interactions cause charge decoherence in double quantum dots, highlighting the dependence on system parameters and the importance of system configuration.

Contribution

It provides analytical and numerical evaluation of relaxation and dephasing rates due to electron-phonon coupling in double quantum dots, considering various system parameters.

Findings

Charge decoherence rates depend strongly on electron confinement and system size.

Energy splitting between charge qubit states is the dominant factor for decoherence.

Double dot configuration details significantly influence decoherence rates.

Abstract

We investigate electron charge decoherence in a laterally-coupled single-electron semiconductor double quantum dot through electron-phonon interaction. We analytically and numerically evaluate the relaxation and dephasing rates due to electron coupling to both acoustic and optical phonons, and explore the system parameter space in terms of interdot distance, strength of single-dot confinement, and inter-dot coupling strength. Our numerical results show that the electron scattering rates are strongly dependent on the strength of the electron confinement and the size of the system. In addition, although the most dominant factor that determines the charge decoherence rate is the energy splitting between the charge qubit states, the details of the double dot configuration is also very important.