Entanglement Resonance in Driven Spin Chains

TL;DR

This paper demonstrates how time-dependent coupling in a spin chain can generate long-distance entanglement, with resonance conditions leading to maximum entanglement, explained through an effective static model.

Contribution

It introduces a novel method to induce long-distance entanglement in spin chains using driven coupling and provides a theoretical framework for understanding entanglement resonance.

Findings

Maximum entanglement occurs when ac frequency matches Zeeman splitting.

Entanglement is maximized with a vanishing dc coupling component.

Numerical simulations support the effective static model predictions.

Abstract

We consider a spin-1/2 anisotropic XY model with time-dependent spin-spin coupling as means of creating long-distance entanglement. We predict the emergence of significant entanglement between the first and the last spin whenever the ac part of the coupling has a frequency matching the Zeeman splitting. In particular, we find that the concurrence assumes its maximum with a vanishing dc part. Mapping the time-dependent Hamiltonian within a rotating-wave approximation to an effective static model provides qualitative and quantitative understanding of this entanglement resonance. Numerical results for the duration of the entanglement creation and its length dependence substantiate the effective static picture.