Ultracold Fermions and theSU(N)Hubbard Model

Probing interactions between ultracold fermions.

At ultracold temperatures, the Pauli exclusion principle suppresses collisions between identical fermions. This has motivated the development of atomic clocks with fermionic isotopes. However, by probing an optical clock transition with thousands of lattice-confined, ultracold fermionic strontium atoms, we observed density-dependent collisional frequency shifts. These collision effects were mea...

Ultracold fermions with repulsive interactions

An ultracold Fermi gas with repulsive interaction has been studied. For weak interactions, the atomic gas is metastable, and the interactions were characterized by obtaining the isothermal compressibility from atomic density profiles. For stronger interactions (kFa  1), rapid conversion into Feshbach molecules is observed. When the conversion rate becomes comparable to the Fermi energy divided...

Superfluidity and magnetism in multicomponent ultracold fermions.

We study the interplay between superfluidity and magnetism in a multicomponent gas of ultracold fermions. Ward-Takahashi identities constrain possible mean-field states describing order parameters for both pairing and magnetization. The structure of global phase diagrams arises from competition among these states as functions of anisotropies in chemical potential, density, or interactions. They...

Open quantum dynamics of ultracold fermions

Background: Degenerate gases of bosons and fermions are routinely generated in a variety of systems in many laboratories worldwide. In recent years there has been a trend to more sophisticated detection methods, capable of measuring higher-order correlations and thus shedding light on the many-body quantum state of the gas. Nevertheless, it is still the case that most measurements involve an ab...

Spin-Orbit Coupling in Ultracold Fermions