Emergence of robust gaps in 2D antiferromagnets via additional spin-1/2 probes

TL;DR

This paper investigates how additional spin-1/2 probes can entangle within 2D antiferromagnetic lattices, revealing robust energy gaps that enable stable entanglement even at higher temperatures, with geometry influencing robustness.

Contribution

It demonstrates the emergence of robust entanglement gaps in 2D antiferromagnets with various geometries, enabling probe-only state descriptions beyond perturbative regimes.

Findings

Robust entanglement gaps appear in 2D antiferromagnets.

Square Heisenberg antiferromagnet shows highest thermal robustness.

Three-leg ladder chain performs best in the ground state.

Abstract

We study the capacity of antiferromagnetic lattices of varying geometries to entangle two additional spin-1/2 probes. Analytical modeling of the Quantum Monte Carlo data shows the appearance of a robust gap, allowing a description of entanglement in terms of probe-only states, even in cases where the coupling to the probes is larger than the gap of the spin lattice and cannot be treated perturbatively. We find a considerable enhancement of the temperature at which probe entanglement disappears as we vary the geometry of the bus and the coupling to the probes. In particular, the square Heisenberg antiferromagnet exhibits the best thermal robustness of all systems, whereas the three-leg ladder chain shows the best performance in the natural quantum ground state.