Confining the state of light to a quantum manifold by engineered two-photon loss
Abstract
Physical systems usually exhibit quantum behavior, such as superpositions and entanglement, only when they are sufficiently decoupled from a lossy environment. Paradoxically, a specially engineered interaction with the environment can become a resource for the generation and protection of quantum states. This notion can be generalized to the confinement of a system into a manifold of quantum states, consisting of all coherent superpositions of multiple stable steady states. We have experimentally confined the state of a harmonic oscillator to the quantum manifold spanned by two coherent states of opposite phases. In particular, we have observed a Schrodinger cat state spontaneously squeeze out of vacuum, before decaying into a classical mixture. This was accomplished by designing a superconducting microwave resonator whose coupling to a cold bath is dominated by photon pair exchange. This experiment opens new avenues in the fields of nonlinear quantum optics and quantum information, where systems with multi-dimensional steady state manifolds can be used as error corrected logical qubits.
Keywords
Cite
@article{arxiv.1412.4633,
title = {Confining the state of light to a quantum manifold by engineered two-photon loss},
author = {Zaki Leghtas and Steven Touzard and Ioan M. Pop and Angela Kou and Brian Vlastakis and Andrei Petrenko and Katrina M. Sliwa and Anirudh Narla and Shyam Shankar and Michael J. Hatridge and Matthew Reagor and Luigi Frunzio and Robert J. Schoelkopf and Mazyar Mirrahimi and Michel H. Devoret},
journal= {arXiv preprint arXiv:1412.4633},
year = {2015}
}