Long-Range Coherence and Multiple Steady States in a Lossy Qubit Array

Understand

We show that a simple experimental setting of a locally pumped and lossy array of two-level quantum systems can stabilize states with strong long-range coherence.

• Indeed, by explicit analytic construction, we show there is an extensive set of steady-state density operators, from minimally to maximally entangled, despite this being an interacting open many-body problem.
• Such nonequilibrium steady states arise from a hidden symmetry that stabilizes Bell pairs over arbitrarily long distances, with unique experimental signatures.
• We demonstrate a protocol by which one can selectively prepare these states using dissipation.