Reduced dynamics with renormalization in solid-state charge qubit measurement

TL;DR

This paper highlights the significance of renormalization as a form of backaction in solid-state charge qubit measurements, which has been largely overlooked in existing quantum measurement theories.

Contribution

It introduces the concept of renormalization as an important backaction effect in solid-state qubit measurement, expanding the understanding beyond dephasing and relaxation.

Findings

Renormalization can significantly affect qubit measurement outcomes.

Traditional theories focus mainly on dephasing and relaxation, neglecting renormalization.

Renormalization effects are context-dependent and can be dominant under certain conditions.

Abstract

Quantum measurement will inevitably cause backaction on the measured system, resulting in the well known dephasing and relaxation. In this report, in the context of solid--state qubit measurement by a mesoscopic detector, we show that an alternative backaction known as renormalization is important under some circumstances. This effect is largely overlooked in the theory of quantum measurement.