Rashi Sachdeva

Interaction-induced effects on Bose-Hubbard parameters

We study the effects of the repulsive on-site interactions on the broadening of the localized Wannier functions used for calculating the parameters to describe ultracold atoms in optical lattices. For this, we replace the common single-particle Wannier functions, which do not contain any information about the interactions, by two-particle Wannier functions (“Twonniers”) obtained from an exact solution which takes the interactions into account. We then use these interaction-dependent basis functions to calculate the Bose–Hubbard model parameters, showing that they are substantially different both at low and high lattice depths, from the ones calculated using single-particle Wannier functions. Our results suggest that density effects are not negligible for many parameter ranges and need to be taken into account in metrology experiments.

Creating superfluid vortex rings in artificial magnetic fields

Artificial gauge fields are versatile tools that allow to influence the dynamics of ultracold atoms in Bose-Einstein condensates. Here we discuss a method of artificial gauge field generation stemming from the evanescent fields of the curved surface of an optical nanofibre. The exponential decay of the evanescent fields leads to large gradients in the generalized Rabi frequency and therefore to the presence of geometric vector and scalar potentials. By solving the Gross-Pitaevskii equation in the presence of the artificial gauge fields originating from the fundamental HE

Density-wave–supersolid and Mott-insulator–superfluid transitions in the presence of an artificial gauge field: A strong-coupling perturbation approach

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Extended Bose-Hubbard model for two-leg ladder systems in artificial magnetic fields

mode of the fibre, we show that vortex rings can be created in a controlled manner. We also calculate the magnetic fields resulting from the higher order HE

Cold atoms in a rotating optical lattice with nearest-neighbor interactions

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Two-leg ladder Bose Hubbard models with staggered fluxes

, TE

Twonniers: Interaction-induced effects on Bose-Hubbard parameters

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Controlling vortex rings in Bose-Einstein condensates using artificial gauge fields

, and TM

Hydrodynamic theory of Rotating Ultracold Supersolids

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Rotation of supersolids in cold atomic condensates

modes and compare them to the fundamental HE