Cluster stability driven by quantum fluctuations

Abstract

By means of an accurate path-integral Monte Carlo we investigate a two-dimensional ensemble of particles interacting via a Lifshitz-Petrich-Gaussian potential. In particular, analysing structures described by a commensurate ratio between the two wave numbers that mark the pattern, the Lifshitz-Petrich-Gaussian boson model may display a stable and well-defined stripe phase lacking any global phase coherence but featuring a superfluid signal along the stripe direction only. Upon increasing quantum fluctuations and quantum-mechanical exchange of bosons, the doubledegeneration of the negative minima in the Fourier transform of the potential is removed at the expense of a density modulation peculiar to a cluster triangular crystal. We also show that this last structure possess all features adhering to the definition of a supersolid phase.

Zonal Estimators for Quasiperiodic Bosonic Many-Body Phases

“…Cluster quasicrystals display peculiar features, not exhibited by simpler quasiperiodic structures. By increasing quantum fluctuations, in fact, a structural transition from quasicrystal to cluster triangular crystal featuring the properties of a supersolid is observed [ 19 , 66 , 67 ]. We point out that the discussed methodology is also useful to analyze the superfluid character of further peculiar inhomogeneous systems such as, for instance, bosons enclosed within spherical traps or subject to a polyhedral-symmetric substrate potential [ 68 , 69 , 70 ].…”

Zonal estimators for quasiperiodic bosonic many-body phases

“…Cluster quasicrystals display peculiar features, not exhibited by simpler quasiperiodic structures. By increasing quantum fluctuations, in fact, a structural transition from quasicrystal to cluster triangular crystal featuring the properties of a supersolid is observed [14,16,17,64].…”

Ground state phase diagram of ultrasoft bosons

“…The theoretical study of the quantum phase transition occurring in the crystallization of soft-core bosons have received a particular attention over the last decade [1][2][3][4][5]. This interest is twofold.…”