The quantum dynamics of atomic magnets, co-tunneling and dipolar-biased tunneling

TL;DR

This paper investigates the quantum dynamics of atomic magnets, focusing on multi-spin tunneling processes like co-tunneling and dipolar-biased tunneling in weakly-coupled Ho$^{3+}$ ions, revealing many-body quantum effects through ac-susceptibility measurements.

Contribution

It introduces a four-body model including nuclear spins to explain two-ions tunneling mechanisms, highlighting co-reversal and entanglement effects in many-body quantum dynamics.

Findings

Evidence of dipolar-biased tunneling and co-tunneling in Ho$^{3+}$ ions.

Identification of entangled pair reversal in magnetic moments.

Insights into many-body quantum behavior in atomic magnets.

Abstract

Multi-spins tunneling cross-relaxations in an ensemble of weakly-coupled Ho$^{3+}$ ions, mediated by weak anisotropic dipolar interactions, can be evidenced by ac-susceptibility measurements in a high temperature regime. Based on a four-body representation, including the rare-earth nuclear spin, two-ions tunneling mechanisms can be attributed to both dipolar-biased tunneling and co-tunneling processes. The co-reversal involving entangled pairs of magnetic moments is discussed with a particular emphasis, giving new evidences to elucidate the many-body quantum dynamics.