Quasicrystalline Bose glass in the absence of disorder and quasidisorder

TL;DR

This paper demonstrates that a Bose Glass phase can emerge in a two-dimensional quasicrystalline lattice without any disorder, driven solely by interactions and quantum effects, challenging the notion that disorder is necessary for such phases.

Contribution

It shows that Bose Glass phases can occur in quasicrystalline lattices without disorder, highlighting the role of interactions and quantum effects in stabilizing this phase.

Findings

Homogeneous Bose-Einstein condensate at weak interactions

Density modulations indicating supersolid-like behavior

Emergence of Bose Glass phase without disorder

Abstract

We study the low-temperature phases of interacting bosons on a two-dimensional quasicrystalline lattice. By means of numerically exact Path Integral Monte Carlo simulations, we show that for sufficiently weak interactions the system is a homogeneous Bose-Einstein condensate, which develops density modulations for increasing filling factor. The simultaneous occurrence of sizeable condensate fraction and density modulation can be interpreted as the analogous, in a quasicrystalline lattice, of supersolid phases occurring in conventional periodic lattices. For sufficiently large interaction strength and particle density, global condensation is lost and quantum exchanges are restricted to specific spatial regions. The emerging quantum phase is therefore a Bose Glass, which here is stabilized in the absence of any source of disorder or quasidisorder, purely as a result of the interplay between quantum effects, particle interactions and quasicrystalline substrate. This finding clearly indicates that (quasi)disorder is not essential to observe Bose Glass physics. Our results are of interest for ongoing experiments on (quasi)disorder-free quasicrystalline lattices.