Coherence and Decoherence in Tunneling between Quantum Dots

TL;DR

This paper investigates the interplay of coherence and decoherence in electron tunneling between coupled quantum dots, using Green's function formalism to analyze time-dependent behavior in various coupling regimes.

Contribution

It introduces a comprehensive Green's function approach to model quantum dot tunneling, explicitly accounting for coupling to a continuum of states and analyzing coherence effects.

Findings

Purely coherent evolution occurs when coupling to the environment is equal for both dots.

A combination of coherent and incoherent behaviors is generally observed.

The formalism provides insights into the transition between coherence and decoherence regimes.

Abstract

Coupled quantum dots are an example of the ubiquitous quantum double potential well. In a typical transport experiment, each quantum dot is also coupled to a continuum of states. Our approach takes this into account by using a Green's function formalism to solve the full system. The time-dependent solution is then explored in different limiting cases. In general, a combination of coherent and incoherent behavior is observed. In the case that the coupling of each dot to the macroscopic world is equal, however, the time evolution is purely coherent.