Open AccessHow to administer an antidote to Schrödinger’s cat
Author(s) -
Juan-Rafael Álvarez,
Mark IJspeert,
Oliver Barter,
Ben Yuen,
Thomas D. Barrett,
Dustin Stuart,
Jerome Dilley,
Annemarie Holleczek,
Axel Kuhn
Publication year - 2022
Publication title -
journal of physics. b, atomic molecular and optical physics/journal of physics. b, atomic, molecular and optical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.725
H-Index - 121
eISSN - 1361-6455
pISSN - 0953-4075
DOI - 10.1088/1361-6455/ac5674
Subject(s) - photon , schrödinger's cat , physics , state (computer science) , beam splitter , quantum mechanics , mathematics , algorithm , laser
In his 1935 Gedankenexperiment, Erwin Schrödinger imagined a box with a cat and a poisonous substance which has a 50% probability of being released, based on the decay of a radioactive atom. As such, the life of the cat and the state of the poison become entangled, and the fate of the cat is determined upon opening the box. We present an experimental technique that keeps the cat alive on any account. This method relies on the time-resolved Hong–Ou–Mandel effect: two long, identical photons impinging on a beam splitter always bunch in either of the outputs. Interpreting the first photon detection as the state of the poison, the second photon is identified as the state of the cat. Even after the collapse of the first photon’s state, we show their fates are intertwined through quantum interference. We demonstrate this by a sudden phase change between the inputs, administered conditionally on the outcome of the first detection, which steers the second photon to a pre-defined output and ensures that the cat is always observed alive.