We experimentally realize spin-tensor momentum coupling (STMC) using three ground Zeeman states coupled by three Raman laser beams in an ultracold atomic system of ${}^{40}\mathrm{K}$ Fermi atoms. This type of STMC consists of two bright-state bands as a spin-orbit coupled spin-1/2 system and one dark-state middle band. Using radio-frequency spin-injection spectroscopy, we investigate the energy band of STMC. It is demonstrated that the middle state is a dark state in the STMC system. The experimental realization of STMC open the door for further exploring exotic quantum matter.

We report the experimental results on the optical control of a $p$-wave Feshbach resonance by utilizing a laser-driven bound-to-bound transition to shift the energy of a closed-channel molecule state. The magnetic field location for the $p$-wave resonance as a function of laser detuning can be captured by a simple formula with essentially one parameter, which describes how sensitively the resonance depends on the laser detuning. The key result of this work is to demonstrate, both experimentally and theoretically, that the ratio between this parameter for the $m=0$ component of the resonance and that for the $m=\pm 1$ component, to a large extent, is universal. We also show that this optical control can create intriguing situations where interesting few- and many-body physics can occur, such as a $p$-wave resonance overlapping with an $s$-wave resonance or the three components of a $p$-wave resonance being degenerate.

We report the experiment on probing the one-body spectral function in a trapped noninteracting ${}^{40}$K Fermi gas by means of the momentum-resolved Raman spectroscopy. The experimental result is in good agreement with the expected quadratic dispersion in the noninteracting regime. Through the comparison with the radio-frequency spectrum, we found that the Raman spectrum shows some new characteristics. DOI: http://dx.doi.org/10.1103/PhysRevA.85.053626 ©2012 American Physical Society

The binding energy of Feshbach molecules from a two-component Fermi gas of ${}^{40}$K atoms has been experimentally measured with the momentum-resolved Raman spectroscopy. Comparing with the radio-frequency spectroscopy, in the present experiment the signal of unpaired (free atoms) and the bound molecules can be directly observed and the binding energy can be simultaneously determined in a single running experiment. The energy-momentum dispersion spectra of the ultracold Fermi gas in the BEC side are also measured and reconstructed. The present experimental technology of the momentum-resolved Raman spectroscopy can be easily extended to perform spatially momentum-resolved Raman spectroscopy and to obtain the response spectra of a homogeneous system in the local density approximation. DOI: http://dx.doi.org/10.1103/PhysRevA.86.033607 ©2012 American Physical Society

We propose and experimentally realize a scheme of the optical nonreciprocity (ONR) using degenerate two-level atoms embedded in an optical ring cavity. For the degenerate transition Fg=4→Fe=3, we first study the cavity-transmission property in different coupling field, and verify that within the strong-coupling regime, the single-dark-state peak formed by electromagnetically induced transparency (EIT) shows ONR. Qualitative theoretical analysis shows that the stable ground-state Zeeman coherence is necessary for intracavity EIT. However, due to the frequency degeneracy, the large Rabi frequency of counter-propagating coupling field can reduce the number of effective atoms and weaken the strong-coupling of the atom-cavity, which determines that ONR based on intracavity EIT occurs only at weaker probe intensity. Furthermore, the ONR transmission with high contrast, linewidth-narrowed and broadband is experimentally demonstrated.

In this Letter we report the experimental results on optical control of a p-wave Feshbach resonance, by utilizing a laser driven bound-to-bound transition to shift the energy of closed channel molecule. The magnetic field location for p-wave resonance as a function of laser detuning can be captured by a simple formula with essentially one parameter, which describes how sensitive the resonance depends on the laser detuning. The key result of this work is to demonstrate, both experimentally and theoretically, that the ratio between this parameter for $m=0$ resonance and that for $m=\pm 1$ resonance, to large extent, is universal. We also show that this optical control can create intriguing situations where interesting few- and many-body physics can occurs, such as a p-wave resonance overlapping with an s-wave resonance or three p-wave resonances being degenerate.