Fig. 1: Lattice potential and sketch of possible phases.
From: Observing the two-dimensional Bose glass in an optical quasicrystal
a, The 2D quasicrystalline optical lattice is generated by superimposing four independent 1D lattices in the x–y plane, marked by small arrows. A deep z lattice (large arrows) divides the system into a series of independent quasi-2D layers. b, Exemplary potential in a single layer. c, Repulsive interactions can delocalize an originally localized disordered system. From top to bottom, the sketches show the transition of the system’s ground state with increasing chemical potential μ, starting from the Anderson insulator (AI) in the non-interacting limit (μ = ϵ0 = 0), where the disorder strength Δ is above the critical disorder strength for localization Δc, over the localized but compressible Bose glass (BG) for weak repulsive interactions where bosons spill over into other low-lying minima and form local superfluid puddles, into the superfluid (SF) when the chemical potential is comparable to or larger than the disorder strength Δ.
