Quantum limited sensitivity of SET-based displacement detectors

TL;DR

This paper investigates the fundamental sensitivity limits of a displacement detector based on a quantum resonator coupled to a single electron transistor, focusing on quantum back-action noise effects.

Contribution

It provides a theoretical analysis of the quantum limits of displacement sensitivity in SET-based detectors, including back-action noise effects and the quantum-classical noise relation.

Findings

Identifies the quantum limit of displacement sensitivity for SET-based detectors

Analyzes the impact of charge fluctuation noise on measurement accuracy

Discusses the interplay between classical and quantum noise components

Abstract

We consider a model of a quantum-mechanical resonator capacitively coupled to a single electron transistor (SET). The tunnel current in the SET is modulated by the vibrations of the resonator, and thus the system operates as a displacement detector. We analyze the effect of the back-action noise of charge fluctuations in the SET onto the dynamics of the resonator and evaluate the displacement sensitivity of the system. The relation between the "classical" and "quantum" parts of the SET charge noise and their effect on the measured system are also discussed.