Position Detector Approaches the Heisenberg Limit

José David Beltrán

Antonio Di Lorenzo

Heisenberg formulated a noise-disturbance principle stating that there is a tradeoff between noise and disturbance when a measurement of position and a measurement of momentum are performed sequentially, and another principle imposing a limitation on the product of the uncertainties in a joint measurement of position and momentum. We prove that the former, the Heisenberg sequential noise-disturbance principle, holds when the detectors are assumed to be initially uncorrelated from each other, but that it can be violated for some properly correlated initial preparations of the detectors.

Gregory S. Bentsen, Emily J. Davis, Monika Schleier-Smith

Jose Beltrán Jiménez, Alfredo Luis

We analyze the performance of nonlinear detection schemes surpassing the Heisenberg limit with semiclassical input states when using realistic detectors having nonunit detection efficiency.

Masanao Ozawa

W. Jia, Victoria Xu, Kevin A. Kuns +97 more

The Heisenberg uncertainty principle dictates that the position and momentum of an object cannot be simultaneously measured with arbitrary precision, giving rise to an apparent limitation known as the standard quantum limit (SQL). Gravitational-wave detectors use photons to continuously measure the positions of freely falling mirrors and so are affected by the SQL. We investigated the performance of the Laser Interferometer Gravitational-Wave Observatory (LIGO) after the experimental realization of frequency-dependent squeezing designed to surpass the SQL. For the LIGO Livingston detector, we found that the upgrade reduces quantum noise below the SQL by a maximum of three decibels between 35 and 75 hertz while achieving a broadband sensitivity improvement, increasing the overall detector sensitivity during astrophysical observations.