Title: Band and correlated insulators of cold fermions in a mesoscopic lattice,
Abstract: We investigate the transport properties of neutral, fermionic atoms passing
through a one-dimensional quantum wire containing a mesoscopic lattice. The
lattice is realized by projecting individually controlled, thin optical
barriers on top of a ballistic conductor. Building an increasingly longer
lattice, one site after another, we observe and characterize the emergence of a
band insulating phase, demonstrating control over quantum-coherent transport.
We explore the influence of atom-atom interactions and show that the insulating
state persists as contact interactions are tuned from moderately to strongly
attractive. Using bosonization and classical Monte-Carlo simulations we analyze
such a model of interacting fermions and find good qualitative agreement with
the data. The robustness of the insulating state supports the existence of a
Luther-Emery liquid in the one-dimensional wire. Our work realizes a tunable,
site-controlled lattice Fermi gas strongly coupled to reservoirs, which is an
ideal test bed for non-equilibrium many-body physics.