Study of maximal bipartite entanglement and robustness in resonating-valence-bond states

TL;DR

This paper investigates maximally entangled resonating-valence-bond states, showing they can be optimized via superpositions, are ground states of a specific model, and are robust against decoherence, offering new insights into quantum entanglement.

Contribution

It introduces a method to maximize bipartite entanglement in RVB states, links these states to an infinite range Heisenberg model, and demonstrates their robustness against decoherence.

Findings

Maximal bipartite entanglement $E_v^2$ increases with system size and saturates.

Maximal $E_v^2$ states are ground states of an infinite range Heisenberg model.

RVB states are robust against local and global phonon interactions.

Abstract

We study maximal bipartite entanglement in valence-bond states and show that the average bipartite entanglement $E_v^2$, between a sub-system of two spins and the rest of the system, can be maximized through a homogenized superposition of the valence-bond states. Our derived maximal $E_v^2$ rapidly increases with system size and saturates at its maximum allowed value. We also demonstrate that our maximal $E^2_v$ states are ground states of an infinite range Heisenberg model (IRHM) and represent a new class of resonating-valence-bond (RVB) states. The entangled RVB states produced from our IRHM are robust against interaction of spins with both local and global phonons and represent a new class of decoherence free states.