Related papers: BCS-BCS crossover between atomic and molecular sup…
Many-body effects may influence properties, such as scattering parameters, nature of pairing, etc., close to a Feshbach resonance in the fermion BEC-BCS crossover problem. We study effects such as these using a tractable crossing-symmetric…
Understanding and controlling interactions of ultracold molecules is a cornerstone of quantum chemistry. While the laboratory creation of degenerate molecular gases comprised of bosonic atoms has unlocked powerful new platforms for quantum…
A Feshbach resonance in the s-wave scattering length occurs if the energy of the two atoms in the incoming open channel is close to the energy of a bound state in a coupled closed channel. Starting from the microscopic hamiltonian that…
We study the ground state and the thermal phase diagram of a two-species Bose-Hubbard model, with $U(1)\times \mathbb{Z}_2$ symmetry, describing atoms and molecules on a 2D optical lattice interacting via a Feshbach resonance. Using quantum…
We consider the behavior of an ultracold Fermi gas across a narrow Feshbach resonance, where the occupation of the closed channel may not be negligible. While the corrections to the single-channel formulae associated with the nonzero…
We study theoretically the di-neutron spatial correlations and the crossover from superfluidity of neutron Cooper pairs in the $^1S_0$ pairing channel to Bose-Einstein condensation (BEC) of di-neutron pairs for both symmetric and neutron…
In a Feshbach resonance, the effective s-wave scattering length grows when one moves toward the resonance point, and eventually diverges at this point. There is one characteristic energy scale, $\delta_c$, defined as, in the negative side…
Resonant interactions associated with the emergence of a bound state constitute one of the cornerstones of modern many-body physics, ranging from Kondo physics, BEC-BCS crossover, to tunable interactions at Feshbach resonances in ultracold…
We present the Bogoliubov theory for the Bose-Einstein condensation of Feshbach molecules in a balanced Fermi mixture. Because the Bogoliubov theory includes (Gaussian) fluctuations, we can in this manner accurately incorporate both the…
Atomic Fermi gases provide an ideal platform for studying the pairing and superfluid physics, using a Feshbach resonance between closed channel molecular states and open channel scattering states. Of particular interest is the strongly…
We consider a mixture of fermionic and bosonic atoms nearby interspecies Feshbach resonances, which have been observed recently in $^6$Li-$^{23}$Na mixture by MIT group, and in $^{40}$K-$^{87}$Rb mixture by JILA group. We point out that the…
We have observed condensation of fermionic atom pairs in the BCS-BEC crossover regime. A trapped gas of fermionic 40K atoms is evaporatively cooled to quantum degeneracy and then a magnetic-field Feshbach resonance is used to control the…
We present the RPA theory of the BEC-BCS crossover in an atomic Fermi gas near a Feshbach resonance that includes the relevant two-body atomic physics exactly. This allows us to determine the probability $Z$ for the dressed molecules in the…
By including the effect of a trap with characteristic energy given by the Fermi temperature $T_F$ in a two-body two-channel model for Feshbach resonances, we reproduce the experimental closed-channel fraction $Z$ across the BEC-BCS…
We study the crossover from the Bardeen-Cooper-Shrieffer (BCS) regime to the Bose-Einstein-condensation (BEC) regime in a quasi-two-dimensional quantum gas of ultracold fermionic atoms. Using an effective two-dimensional Hamiltonian with…
Strong evidence for pairing and superfluidity has recently been found in atomic Fermi gases at the BCS-BEC crossover both in collective modes and RF excitation energies. It is argued that the scale for the effective pairing gaps measured in…
We study resonantly-paired s-wave superfluidity in a degenerate gas of two species (hyperfine states labeled by $\uparrow,\downarrow$) of fermionic atoms when the numbers $N_{\uparrow}$ and $N_{\downarrow}$ of the two species are {\it…
We study the properties of dilute bosons immersed in a single component Fermi sea across a broad boson-fermion Feshbach resonance. The stability of the mixture requires that the bare interaction between bosons exceeds a critical value,…
Recent experimental realizations of superfluid mixtures of Bose and Fermi quantum gases provide a unique platform for exploring diverse superfluid phenomena. We study dipole oscillations of a double superfluid in a cigar-shaped optical…
We investigate theoretically Fermionic superfluidity induced by Feshbach resonance in the orbital p-wave channel. We show that, due to the dipole interaction, the pairing is extremely anisotropic. When this dipole interaction is relatively…