Ever since the first experimental realization of bosonic Mott insulators almost 20 years ago, Bosons in optical lattice have served as one of the paradigmatic many-body systems to study non-equilibrium many-body dynamics. In this talk, I will present two new developments in this field.
By using resonant Floquet engineering (shaking) we have been able to resonantly couple and hybridize the lowest two bands of an optical lattice and to thereby control the character of the Mott transition: By changing the drive parameters, we are able to turn the Mott transition from a continuous into a discontinuous transition and could observe the associated metastability and hysteresis. Our results agree with numerical simulations in 1D and pave the way for exploring the crucial role of quantum fluctuations in discontinuous transitions.
Using an optical quasicrystal, i.e., an eightfold symmetric quasiperiodic optical lattice, we have very recently been able to study the localisation transition of Bosons in 2D and I will present first experimental data on the Bose glass phase in two dimensions. Here, the quasiperiodic modulation plays the role of the disorder. Crucially, their long range ordered nature excludes the type of rare thermalising regions often quoted as destabilising 2D many-body localised systems.