Moiré-related physics in twisted bilayer two-dimensional (2D) materials has attracted widespread interest in condensed-matter physics. Simulation of moiré related physics in cold atom platforms is expected to outperform 2D materials thanks to its advantage of higher tunablility. Here, we demonstrate that the cold atom platform enables an alternative mechanism of moiré lattice formation, induced by interlayer interaction with intrinsic “dynamical” character, in contrast with conventional moiré lattice induced by “static” ways such as single-particle interlayer tunneling. Specifically, we consider a twisted bilayer Bose-Hubbard model with vanishing interlayer tunneling, and the bilayer is solely coupled through interlayer interactions that originate from the contact interaction of atoms. We find that this system hosts a plethora of intriguing phases unique to this dynamical lattice, including a variety of Mott insulator (MI) and superfluid (SF) phases either preserving or breaking moiré lattice symmetry, phases with one layer in SF and the other in MI, “interlocked” MI, and self-localized phases at commensurate twist angles, which exhibits the characteristics of Bose glass and quasi-many-body localization in the absence of (quasi)disorder or quasicrystalline lattices. Our prediction can be readily observed in current experimental setups of twisted bilayer optical lattices, opening up alternative avenues for exploring the rich physics of interaction induced moiré systems in cold atoms.

Close

PrevNext

View figure in article

• Cold gases in optical lattices
• Ultracold gases