Many-spin entanglement in multiple quantum NMR with a dipolar ordered initial state

TL;DR

This paper explores how multiple quantum NMR with a dipolar ordered initial state can be used to detect and analyze many-spin entanglement in molecular gases within nanocavities, providing insights into quantum correlations.

Contribution

It introduces a method to estimate many-spin entanglement using the second moment of MQ NMR coherence intensities in a dipolar ordered state.

Findings

Entanglement varies with temperature and number of spins.

The second moment bounds the quantum Fisher information.

Potential for exploring quantum correlations in nanocavity gases.

Abstract

Multiple quantum (MQ) NMR with a dipolar ordered initial state opens new possibilities for the exploration of many-spin entanglement. In this paper, we investigate many-spin entanglement in a gas of spin-carrying molecules (atoms) in nanocavities in the conditions of MQ NMR with a dipolar ordered initial state. The second moment of the distribution of the intensities of MQ NMR coherences, which provides a lower bound on the quantum Fisher information, is used for an estimate of the number of the entangled spins. Many-spin entanglement is investigated at different temperatures and different numbers of spins.