Long distance entanglement in one-dimensional quantum systems under sinusoidal deformation

TL;DR

This paper explores how sinusoidal deformation in one-dimensional quantum spin systems enables long-distance entanglement between distant spins, which remains robust against temperature and thermal fluctuations.

Contribution

It introduces a sinusoidal deformation method that facilitates long-distance entanglement in quantum spin chains, a novel approach for quantum information applications.

Findings

Long-distance entanglement occurs for deformation parameter  2.

Entanglement persists at finite temperatures, decaying algebraically with system size.

Robustness of entanglement against thermal fluctuations is demonstrated.

Abstract

We investigate entanglement generation in one-dimensional quantum spin systems with the sinusoidal deformation. In the system, the energy scale of each local term in the Hamiltonian is modified according to a position-dependent function \sin^\alpha[\frac{\pi}{N} (x - \frac{1}{2})], where x is the position of the local term and N is the length of the system. We show that at zero temperature the system with \alpha \ge 2 is able to generate a sizable entanglement between two spins at open edges even when the two spins are infinitely far apart. This long-distance entanglement is rather robust against thermal fluctuations and survives up to a temperature that decays with the system size slowly, in an algebraic form.