The evolution of two-component cold atoms on a ring with spin-orbit coupling has been studied analytically for the case with N noninteracting particles. Then, the effect of interaction is evaluated numerically via a t...The evolution of two-component cold atoms on a ring with spin-orbit coupling has been studied analytically for the case with N noninteracting particles. Then, the effect of interaction is evaluated numerically via a two-body system. Two cases are considered： （i） Starting from a ground state the evolution is induced by a sudden change of the laser field, and （ii） the evolution starting from a superposition state. Oscillating persistent spin-currents have been found. A set of formulae have been derived to describe the period and amplitude of the oscillation. Based on these formulae the oscillation can be well controlled via adjusting the parameters of the laser beams. In particular, it is predicted that movable stripes might emerge on the ring.展开更多
This paper studies theoretically the spin evolution of a Bose-Einstein condensate starting from a mixture of two or three groups of 52Cr （spin-3） atoms in an optical trap. The initial state is so chosen that the con...This paper studies theoretically the spin evolution of a Bose-Einstein condensate starting from a mixture of two or three groups of 52Cr （spin-3） atoms in an optical trap. The initial state is so chosen that the condensate has total magnetization zero so that the system does not distinguish up and down. It is assumed that the system is very dilute （particle number is very small）, the temperature is very low, and the frequency of the harmonic trap is large enough. In these situations, the deviation caused by the neglect of the dipole-dipole interaction and by using the single-mode approximation is reduced. A theoretical calculation beyond the mean field theory is performed and the numerical results are helpful for the evaluation of the unknown strength go.展开更多
A complete set of quantum numbers for the eigenstates of the Na_(3)^(+) system has been introduced. The structure of the ground rotation band has been deduced based on symmetry considerations. This band is found to be...A complete set of quantum numbers for the eigenstates of the Na_(3)^(+) system has been introduced. The structure of the ground rotation band has been deduced based on symmetry considerations. This band is found to be different from that of H3^(+), though they are similar in dynamics.展开更多
The coupled Gross–Pitaevskii equations for two-species BEC have been solved analytically under the Thomas-Fermi approximation(TFA). Based on the analytical solution, two formulae are derived to relate the particle nu...The coupled Gross–Pitaevskii equations for two-species BEC have been solved analytically under the Thomas-Fermi approximation(TFA). Based on the analytical solution, two formulae are derived to relate the particle numbers N_A and N_B with the root mean square radii of the two kinds of atoms. Only the case that both kinds of atoms have nonzero distribution at the center of an isotropic trap is considered. In this case the TFA has been found to work nicely. Thus, the two formulae are applicable and are useful for the evaluation of N_A and N_B.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.10874249)
文摘The evolution of two-component cold atoms on a ring with spin-orbit coupling has been studied analytically for the case with N noninteracting particles. Then, the effect of interaction is evaluated numerically via a two-body system. Two cases are considered： （i） Starting from a ground state the evolution is induced by a sudden change of the laser field, and （ii） the evolution starting from a superposition state. Oscillating persistent spin-currents have been found. A set of formulae have been derived to describe the period and amplitude of the oscillation. Based on these formulae the oscillation can be well controlled via adjusting the parameters of the laser beams. In particular, it is predicted that movable stripes might emerge on the ring.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10874249 and 11075223)
文摘This paper studies theoretically the spin evolution of a Bose-Einstein condensate starting from a mixture of two or three groups of 52Cr （spin-3） atoms in an optical trap. The initial state is so chosen that the condensate has total magnetization zero so that the system does not distinguish up and down. It is assumed that the system is very dilute （particle number is very small）, the temperature is very low, and the frequency of the harmonic trap is large enough. In these situations, the deviation caused by the neglect of the dipole-dipole interaction and by using the single-mode approximation is reduced. A theoretical calculation beyond the mean field theory is performed and the numerical results are helpful for the evaluation of the unknown strength go.
基金the National Natural Science Foundation of China under Grant No.19875084.
文摘A complete set of quantum numbers for the eigenstates of the Na_(3)^(+) system has been introduced. The structure of the ground rotation band has been deduced based on symmetry considerations. This band is found to be different from that of H3^(+), though they are similar in dynamics.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11372122,11274393,11574404,and 11275279the Open Project Program of State Key Laboratory of Theoretical Physics,Institute of Theoretical Physics,Chinese Academy of Sciences,China+1 种基金the National Basic Research Program of China(2013CB933601)Guangdong Natural Science Foundation(2016A030313313)
文摘The coupled Gross–Pitaevskii equations for two-species BEC have been solved analytically under the Thomas-Fermi approximation(TFA). Based on the analytical solution, two formulae are derived to relate the particle numbers N_A and N_B with the root mean square radii of the two kinds of atoms. Only the case that both kinds of atoms have nonzero distribution at the center of an isotropic trap is considered. In this case the TFA has been found to work nicely. Thus, the two formulae are applicable and are useful for the evaluation of N_A and N_B.
