We systematically investigate the topological superfluidity of a Rydberg-dressed Fermi gas, where the soft-core effective interaction is of finite radius $R_c$ due to the blockade effect. We calculate the quantum phase diagram within the mean-field approximation and find three distinct phases: polar $\left(p_z\right)$, axial $\left(p_x+i{p}_y\right)$, and axiplanar $\left(p_x+i{\beta }_p{p}_y\right)$ phases. The tricritical point is around $R_c{k}_F\sim 1$, where $k_F$ is the Fermi wave vector. We further derive the Ginzburg–Landau theory to explain the phase diagram and estimate the transition temperature to be about $0.1E_F$ in the current experimental regime of ${}^6\mathrm{Li}$. Our work paves the way for future studies on exotic topological superfluids and related quantum phase transitions.

We study the Josephson-like tunneling in two-component Bose-Einstein condensates coupled with microwave field in respond to various attractive and repulsive atomic interaction under the various aspect ratio of trapping potential and the gravitational field. It is very interesting to find that the dynamic of Josephson-like tunneling can be controlled from fast damped oscillations and asymmetric occupation to nondamped oscillation and symmetric occupation.

A concept of measuring the quantum distance between two different quantum states that is called quantum information metric has been presented. The holographic principle (anti–de Sitter/conformal field theory) suggests that the quantum information metric $G_{\lambda \lambda }$ between perturbed state and unperturbed state in field theory has a dual description in the classical gravity. In this work we calculate the quantum information metric of a theory that is dual to a conical defect geometry and we show that it is $n$ times the one of its covering space. We also give a holographic check for our result in the gravity side. Meanwhile, it was argued that $G_{\lambda \lambda }$ is dual to a codimension-one surface in spacetime and satisfies $G_{\lambda \lambda }=n_d·\mathrm{Vol}({\mathrm{\Sigma }}_{\max })/L^d$. We show that the coefficient $n_d$ for conical defect should be rescaled by $n^2$ from the one for anti–de Sitter space. A limit case of conical defect—the massless Banados-Teitelboim-Zannelli (BTZ) black hole—is also considered. We show that the quantum information metric of a massless BTZ black hole disagrees with the one obtained by taking the vanishing temperature limit in BTZ black hole. This provides a new arena in differentiating the different phases between BTZ spacetime and its massless cousin.

We investigate the low energy excitations of a dilute atomic Bose gas confined in a anharmonic trap interacting with repulsive forces. The dispersion law of both surface and compression modes are derived and analyzed for large numbers of atoms in the trap, which show two branches of excitation and appear a two critical value. For a upper limit, BEC can be unstable with respect to some specific collective excitation, while for the lower limit, the frequency of collective excitation under anharmonic influence can be effectively lower than that without anharmonicity. Our work reveals the key role played by the anharmonicity and interatomic forces which introduce a rich structure in the dynamic behavior of these new many-body systems.

A concept of measuring the quantum distance between two different quantum states which is called quantum information metric is presented. The holographic principle (AdS/CFT) suggests that the quantum information metric $G_{\lambda\lambda}$ between perturbed state and unperturbed state in field theory has a dual description in the classical gravity. In this work we calculate the quantum information metric of a theory which is dual to a conical defect geometry and we show that it is $n$ times the one of its covering space. We also give a holographic check for our result in the gravity side. Meanwhile, it was argued that $G_{\lambda\lambda}$ is dual to a codimension-one surface in spacetime and satisfies $G_{\lambda\lambda}=n_{d}\cdot\mbox{Vol}(\Sigma_{max})/L^{d}$. We show that the coefficient $n_d$ for conical defect should be rescaled by $n^2$ from the one for AdS. A limit case of conical defect --- the massless BTZ black hole--- is also considered. We show that the quantum information metric of the massless BTZ black hole disagrees with the one obtained by taking the vanishing temperature limit in BTZ black hole. This provides a new arena in differiating the different phases between BTZ spacetime and its massless cousin.

We show that how to generate propagation of spin degree in spin-symmetric exciton-polariton condensates in a semiconductor microcavity. Due to the stimulated spin-dependent scattering between hot excitons and condensates, exciton polaritons form a circular polarized condensate with spontaneous breaking of the spin rotation symmetry. The spin antiferromagnetic state is developed evidently from the density and spin flow pumped by localized laser source. The low energy spin current is identified where the steady state is characterized by the oscillating spin pattern. Finally, we predict via simulation how to dynamical generation of phase slip where ring-shape phase jump shows the behavior of splitting and joining together.