Report

Mechanically Detecting and Avoiding the Quantum Fluctuations of a Microwave Field

Science  15 May 2014:

DOI: 10.1126/science.1253258

You are currently viewing the abstract.

View Full Text

Via your Institution

Log in through your institution

Log in through your institution


Abstract

Quantum fluctuations of the light field used for continuous position detection produces stochastic back-action forces and ultimately limits the sensitivity. To overcome this limit, the back-action forces can be avoided by giving up complete knowledge of the motion, and these types of measurements are called “back-action evading” or “quantum nondemolition” detection. We present continuous two-tone back-action evading measurements with a superconducting electromechanical device, realizing three long-standing goals: detection of back-action forces due to the quantum noise of a microwave field, reduction of this quantum back-action noise by 8.5 ± 0.4 dB, and measurement imprecision of a single quadrature of motion 2.4 ± 0.7 dB below the mechanical zero-point fluctuations. Measurements of this type will find utility in ultrasensitive measurements of weak forces and nonclassical states of motion.

View Full Text