We use quantum kinetic theory to calculate the thermoelectric transport properties of the two-dimensional single-band Fermi-Hubbard model in the weak coupling limit. For generic filling, we find that the high-temperature limiting behaviors of the electrical (∼T) and thermal (∼T2) resistivities persist down to temperatures of order the hopping matrix element T∼t, almost an order of magnitude below the bandwidth. At half filling, perfect nesting leads to anomalous low-temperature scattering and nearly T-linear electrical resistivity at all temperatures.

Motivated by recent experiments, we calculate particle emission from a Bose-Einstein condensate trapped in a single deep well of a one-dimensional lattice when the interaction strength is modulated. In addition to pair emission, which has been widely studied, we observe single-particle emission. Within linear response, we are able to write closed-form expressions for the single-particle emission rates and reduce the pair emission rates to one-dimensional integrals.

We model the superfluid to Mott insulator transition for a Bose gas on a lattice with two inequivalent sublattices. Using the Gutzwiller ansatz, we produce phase diagrams and provide an understanding of the interplay between superfluidity on each sublattice. We explore how the Mott lobes split and describe the experimental signatures. © 2021 American Physical Society.

We examine the discontinuous first-order superfluid He3 A to B transition in the vicinity of the polycritical point (2.232 mK and 21.22 bar). We find path-dependent transitions: cooling at fixed pressure yields a well-defined transition line in the temperature-pressure plane, but this line can be reliably crossed by depressurizing at nearly constant temperature after transiting Tc at a higher pressure. This path dependence is not consistent with any of the standard B-phase nucleation mechanisms in the literature.

We present a sequence of driven-dissipative protocols for controlling cold atoms in tilted optical lattices. These experimentally accessible examples are templates that demonstrate how dissipation can be used to manipulate quantum many-body systems. We consider bosonic atoms trapped in a tilted optical lattice, immersed in a superfluid bath, and excited by coherent Raman lasers. With these ingredients, we are able to controllably transport atoms in the lattice and produce self-healing quantum states: a Mott insulator and the topologically ordered spin-1 Affleck-Kennedy-Lieb-Tasaki state.

Experiments on graphene bilayers, where the top layer is rotated with respect to the one below, have displayed insulating behavior when the moiré bands are partially filled. We calculate the charge distributions in these phases, and estimate the excitation gaps. © 2021 authors. Published by the American Physical Society.

We use kinetic theory to model the dynamics of a small Bose condensed cloud of heavy particles moving through a larger degenerate Fermi gas of light particles. Varying the Bose-Fermi interaction, we find a crossover between bulk- and surface-dominated regimes - where scattering occurs throughout the Bose cloud or solely on the surface, respectively. We calculate the damping and frequency shift of the dipole mode in a harmonic trap as a function of the magnetic field controlling an interspecies Feshbach resonance.

The investigation of transport properties in normal liquid helium-3 and its topological superfluid phases provides insights into related phenomena in electron fluids, topological materials, and putative topological superconductors. It relies on the measurement of mass, heat, and spin currents, due to system neutrality. Of particular interest is transport in strongly confining channels of height approaching the superfluid coherence length, to enhance the relative contribution of surface excitations, and suppress hydrodynamic counterflow.

An amendment to this paper has been published and can be accessed via a link at the top of the paper. © 2020, The Author(s).

Selection rules are of vital importance in determining the basic optical properties of atoms, molecules and semiconductors. They provide general insights into the symmetry of the system and the nature of relevant electronic states. A two-dimensional electron gas in a magnetic field is a model system where optical transitions between Landau levels (LLs) are described by simple selection rules associated with the LL index N. Here we examine the inter-LL optical transitions of high-quality bilayer graphene by photocurrent spectroscopy measurement.