Measurement time in double quantum dots

TL;DR

This paper models the measurement process in double quantum dots, deriving the decoherence dynamics and identifying a minimum measurement time through a dynamical approach involving a detector modeled as a point contact.

Contribution

It introduces a dynamical model for decoherence in double quantum dots interacting with a point contact detector, revealing a fundamental minimum measurement time.

Findings

Derived a model for decoherence dynamics in double quantum dots

Calculated the measurement time for the quantum system

Identified a minimum possible measurement time

Abstract

In this letter, we have considered an electron in a double quantum dot system interacting with a detector represented by a point contact. We present a dynamical model for the gradual decoherence of the density matrix due to the interaction with the detector. The interaction of the qubit (quantum system) on the quantum point contact (environment) leads to a discrete set of pointer states of the double quantum dot (apparatus). The necessary time for the qubit decoherence process (measurement time) has been calculated through this model. The existence of a minimum time for the quantum measurement has been obtained.