Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Spotlight on Optics: Generation of highly pure Schrödinger's cat states and real-time quadrature measurements via optical filtering

Published

Author(s)

Thomas Gerrits

Abstract

Schrödinger cat states are fundamental quantum states with no classical analogues. Schrödinger Gedanken experiment of 1935 described a cat apparently held in a superposition of alive and dead states [1], but we now use Schrödinger cat to refer to a quantum state that is a superposition of two highly distinguishable classical states. Such states could be useful for quantum information processing and metrology beyond the quantum limit. Making Schrödinger cat states in travelling optical modes is especially desirable, because they can be used for quantum communication, computing and interferometry. In their experiment, Asavanant et al. demonstrate the generation of high-purity optical Schrödinger cat states in a travelling optical mode using a continuous wave (CW) squeezer and subsequent photon subtraction. The non-Gaussian operation of photon subtraction projects the squeezed vacuum into a squeezed single photon state, a close approximation to the desired optical Schrödinger cat state. High purities can be achieved with such CW sources. However, the cat state’s location in time could only be determined in post-processing until now. Asavanant et al. demonstrate CW-squeezing mode matching through optical and electrical filtering, and consequently observe a cat state in real-time without the need of post-processing. Thus, the cat state generated from the CW squeezer has a deterministic appearance in time, in principle allowing for feed-forward operation and interference on beam splitters, a necessary ingredient for continuous variable quantum computing. [1] Schrödinger, E. Die gegenwartige Situation in der Quantenmechanik. Naturwissenschaften 23, 807-812 (1935)
Citation
Optics Express
Volume
25

Citation

Gerrits, T. (2017), Spotlight on Optics: Generation of highly pure Schrödinger's cat states and real-time quadrature measurements via optical filtering, Optics Express, [online], https://doi.org/10.1364/OE.25.032227 (Accessed June 21, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created December 25, 2017, Updated November 10, 2018