Magnetic monopole induced polarons in atomic superlattices

TL;DR

This paper explores how magnetic monopoles in atomic superlattices can induce a new type of polaron, called monopole-cored polaron, characterized by enhanced mobility due to magnon dressing effects.

Contribution

It introduces the concept of monopole-cored polarons in atomic pseudospin chains and analyzes their unique properties and interactions, including anti-trapping behavior and bipolarons.

Findings

Monopoles excite a virtual magnon cloud, forming monopole-cored polarons.

Magnon dressing enhances monopole mobility, leading to anti-trapping effects.

Heterogeneous bipolarons can form with combined north and south monopoles.

Abstract

Magnetic monopoles have been realized as emergent quasiparticles in both condensed matter and ultracold atomic platforms, with growing interests in the coupling effects between the monopole and different magnetic quasiparticles. In this work, interaction effects between monopoles and magnons are investigated for an atomic pseudospin chain. We reveal that the monopole can excite a virtual magnon cloud in the paramagnetic chain, thereby giving rise to a new type of polaron, the monopole-cored polaron (McP). The McP is composed of the monopole as the impurity core and the virtual magnon excitation as the dressing cloud. The magnon dressing facilitates the Dirac string excitation and impacts the monopole hopping. This induces an anti-trapping effect of the McP, which refers to the fact that the dressing enhances the mobility of the McP, in contrast to the self-trapping of the common polarons. Moreover, heterogeneous bipolarons are shown to exist under the simultaneous doping of a north and a south monopole. The heterogeneous bipolaron possesses an inner degree of freedom composed of two identical impurities. Our investigation sheds light on the understanding of how the coupling between the impurity core and the dressing cloud can engineer the property of the polaron