Measurement induced quantum-classical transition

TL;DR

This paper models how measurement-induced dephasing affects a quantum system by coupling an oscillator to an electrical contact, revealing damping and heating effects observable in current-voltage behavior.

Contribution

It introduces a zero-temperature, non-equilibrium model of a quantum-classical transition via measurement, highlighting damping and heating phenomena in a coupled oscillator-electron system.

Findings

Oscillator dynamics become damped due to measurement.

Effective temperature is set by the voltage drop.

Quantum heating and damping influence the current-voltage characteristic.

Abstract

A model of an electrical point contact coupled to a mechanical system (oscillator) is studied to simulate the dephasing effect of measurement on a quantum system. The problem is solved at zero temperature under conditions of strong non-equilibrium in the measurement apparatus. For linear coupling between the oscillator and tunneling electrons, it is found that the oscillator dynamics becomes damped, with the effective temperature determined by the voltage drop across the junction. It is demonstrated that both the quantum heating and the quantum damping of the oscillator manifest themselves in the current-voltage characteristic of the point contact.