Projective versus weak measurement of charge in a mesoscopic conductor

TL;DR

This paper compares the effects of weak and strong measurements on the charge dynamics of a quantum dot, revealing a transition from system-driven to measurement-driven universal behavior.

Contribution

It introduces a detailed analysis of charge measurement regimes in mesoscopic conductors, highlighting the transition from intrinsic dynamics to measurement-dominated behavior.

Findings

Weak and strong measurements produce distinct charge-charge correlators.

Multiple projective measurements induce a transition to universal measurement-governed dynamics.

The study provides insights into measurement back-action in quantum dot systems.

Abstract

We study the charge dynamics of a quantum dot as measured by a nearby quantum point contact probing the dot via individual single-particle wave packets. We contrast the two limiting cases of weak and strong system--detector coupling exerting vanishing and strong back-action on the system and analyze the resulting differences in the charge-charge correlator. Extending the study to multiple projective measurements modelling a continuous strong measurement, we identify a transition from a charge dynamics dominated by the system's properties to a universal dynamics governed by the measurement.