2021/04/30 by Peter Groszkowski, Martin Koppenhöfer, Hoi-Kwan Lau +1 · 2 citations
Physics and Astronomy · #quant-ph #cond-mat.quant-gas
paper · pdf · doi:10.1103/physrevx.12.011015
published as Physical Review X 12, 011015 (2022) · equivalent to published version, 18+14 pages, 10+7 figures
arxiv created 2022/02/06 · arxiv updated 2022/02/08
We revisit the dissipative approach to producing and stabilizing spin-squeezed states of an ensemble of N two-level systems, providing a detailed analysis of two surprising yet generic features of such protocols. The first is a macroscopic sensitivity of the steady state to whether N is even or odd. We discuss how this effect can be avoided (if the goal is parity-insensitive squeezing), or could be exploited as a new kind of sensing modality to detect the addition or removal of a single spin. The second effect is an anomalous emergent long timescale and a "prethermalized" regime that occurs for even weak single-spin dephasing. This effect allows one to have strong spin squeezing over a long transient time even though the level of spin squeezing in the steady state is very small. We also discuss a general hybrid-systems approach for implementing dissipative spin squeezing that does not require squeezed input light or complex multi-level atoms, but instead makes use of bosonic reservoir-engineering ideas. Our protocol is compatible with a variety of platforms, including trapped ions, NV defect spins coupled to diamond optomechanical crystals, and spin ensembles coupled to superconducting microwave circuits.