Bose Glass Transition in a Two-Dimensional Optical Quasicrystal*

A quasicrystal is a non-periodic yet long-range ordered structure, which provides an fascinating testing ground for a variety of phenomena, particularly those of disordered many-body systems. One such intriguing phenomenon is localization, which can typically be induced by either the presence of sufficient disorder, or strong interactions, leading to Anderson or Mott insulators respectively. Interestingly, the interplay of interactions and disorder can produce a new state, the so-called Bose glass phase.

In this talk I will report on the realisation of a two-dimensional Bose glass phase, and the observation of the localization transition driven by disorder, which was detected with both condensate fraction and coherence measurements. Remarkably, interactions can revive the coherence of the localized state, leading to a shift in the phase transition. Our findings pave the way for further studying novel phenomena of disordered systems, such as many-body localization.