Quantum orientational melting of mesoscopic clusters

TL;DR

This paper investigates how quantum fluctuations induce disordering in two-dimensional mesoscopic electron or magnetoexciton clusters, revealing two distinct quantum melting transitions at different fluctuation strengths.

Contribution

It provides a detailed phase diagram of quantum disordering phenomena in mesoscopic clusters using path integral Monte Carlo simulations, highlighting two types of orientational melting transitions.

Findings

Transition from ordered to orientationally disordered shells at q<0.01

Transition to a disordered or superfluid state at q=0.1

Identification of quantum melting phenomena in mesoscopic clusters

Abstract

By path integral Monte Carlo simulations we study the phase diagram of two - dimensional mesoscopic clusters formed by electrons in a semiconductor quantum dot or by indirect magnetoexcitons in double quantum dots. At zero (or sufficiently small) temperature, as quantum fluctuations of particles increase, two types of quantum disordering phenomena take place: first, at small values of quantum de Boer parameter q < 0.01 one can observe a transition from a completely ordered state to that in which different shells of the cluster, being internally ordered, are orientationally disordered relative to each other. At much greater strengths of quantum fluctuations, at q=0.1, the transition to a disordered (superfluid for the boson system) state takes place.