Time-Continuous Bell Measurements

Author(s)
Sebastian Hofer, Denis V. Vasilyev, Markus Aspelmeyer, Klemens Hammerer
Abstract

We combine the concept of Bell measurements, in which two systems are projected into a maximally entangled state, with the concept of continuous measurements, which concerns the evolution of a continuously monitored quantum system. For such time-continuous Bell measurements we derive the corresponding stochastic Schrödinger equations, as well as the unconditional feedback master equations. Our results apply to a wide range of physical systems, and are easily adapted to describe an arbitrary number of systems and measurements. Time-continuous Bell measurements therefore provide a versatile tool for the control of complex quantum systems and networks. As examples we show that (i) two two-level systems can be deterministically entangled via homodyne detection, tolerating photon loss up to 50%, and (ii) a quantum state of light can be continuously teleported to a mechanical oscillator, which works under the same conditions as are required for optomechanical ground-state cooling.

Organisation(s)
Quantum Optics, Quantum Nanophysics and Quantum Information
External organisation(s)
Gottfried Wilhelm Leibniz Universität Hannover, Max-Planck-Institut für Gravitationsphysik (Albert Einstein Institut)
Journal
Physical Review Letters
Volume
111
No. of pages
6
ISSN
0031-9007
DOI
https://doi.org/10.1103/PhysRevLett.111.170404
Publication date
10-2013
Peer reviewed
Yes
Austrian Fields of Science 2012
103036 Theoretical physics, 103025 Quantum mechanics
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/e7f47f43-13ca-46af-adb4-5b0f4635c2c6