Exact Results for a Boundary-Driven Double Spin Chain and Resource-Efficient Remote Entanglement Stabilization

TL;DR

This paper presents an exact solution for the steady state of boundary-driven double spin chains, revealing pure entangled states and correlation effects, with potential applications in quantum information processing.

Contribution

The authors derive an exact steady state solution for boundary-driven XX spin chains with non-uniform couplings, enabling resource-efficient remote entanglement stabilization.

Findings

Pure entangled steady states are achievable without squeezed light.

The system exhibits emergent pairing of hole excitations.

Insights into boundary-driven dissipative spin chains mapping to fermionic models.

Abstract

We derive an exact solution for the steady state of a setup where two $XX$-coupled $N$-qubit spin chains (with possibly non-uniform couplings) are subject to boundary Rabi drives, and common boundary loss generated by a waveguide (either bidirectional or unidirectional). For a wide range of parameters, this system has a pure entangled steady state, providing a means for stabilizing remote multi-qubit entanglement without the use of squeezed light. Our solution also provides insights into a single boundary-driven dissipative $XX$ spin chain that maps to an interacting fermionic model. The non-equilibrium steady state exhibits surprising correlation effects, including an emergent pairing of hole excitations that arises from dynamically constrained hopping. Our system could be implemented in a number of experimental platforms, including circuit QED.