Publications (9)16.85 Total impact
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ABSTRACT: We present a variational study of the spin1 Bose gases in a harmonic trap with threedimensional spinorbit coupling of Weyl type. For weak spinorbit coupling, we treat the singleparticle ground states as the form of perturbational harmonic oscillator states in the lowest total angular momentum manifold with $j=1, m_j=1,0,1$. When the twobody interaction is considered, we set the trail order parameter as the superposition of three degenerate singleparticle groundstates and the weight coefficients are determined by minimizing the energy functional. Two ground state phases, namely the magnetic and the nematic phases, are identified depending on the spinindependent and the spindependent interactions. Unlike the nonspinorbitcoupled spin1 BoseEinstein condensate for which the phase boundary between the magnetic and the nematic phase lies exactly at zero spindependent interaction, the boundary is modified by the spinorbitcoupling. We find the magnetic phase is featured with phaseseparated density distributions, 3D skyrmionlike spin textures and competing magnetic and biaxial nematic orders, while the nematic phase is featured with miscible density distributions, zero magnetization and spatially modulated uniaxial nematic order. The emergence of higher spin order creates new opportunities for exploring spintensorrelated physics in spinorbit coupled superfluid.  [Show abstract] [Hide abstract]
ABSTRACT: We investigate the groundstate and magnetic properties of a dipolar spin1 BoseEinstein condensate trapped in a symmetric doublewell potential. In particular, we focus on the spinvortex states by assuming that each potential well is highly pancake shaped. We show that the presence of the doublewell potential gives rise to two different spin configurations for the spinvortex pair states. We also study the response of the coupled spinvortex pair to static transverse magnetic fields.  [Show abstract] [Hide abstract]
ABSTRACT: We investigate continuoustime quantum walks of two fermionic atoms loaded in onedimensional optical lattices with onsite interaction and subjected to a Zeeman field. The quantum walks are accompanied by spinflipping processes. We calculate the timedependent density distributions of the two fermions with opposite spins which are initially positioned at the center site by means of an exact numerical method. Besides the usual fast linear expansion behavior, we find an interesting spinflippinginduced localization in the time evolution of density distributions. We show that the fast linear expansion behavior can be restored by simply ramping up the Zeeman field or further increasing the spinflipping strength. The intrinsic origin of this exotic phenomenon is attributed to the emergence of a flat band in the singleparticle spectrum of the system. Furthermore, we investigate the effect of onsite interaction on the dynamics of the quantum walkers. The twoparticle correlations are calculated and the signal of localization is also shown therein. A simple potential experimental application of this interesting phenomenon is proposed.  [Show abstract] [Hide abstract]
ABSTRACT: We propose to experimentally realize an oddparity eigenstate $b\ensuremath{\rangle}$ of two atoms in a double well. The occupation probability of this state shows evident dependence on the interaction, distinct from the result of twomode model adopted in the Heidelberg experiment. The tunneling dynamics of two atoms starting from the NOON state with infinite barrier height can be derived from the exactly solved model of a $\ensuremath{\delta}$barrier split double well based on a Bethe ansatz type hypothesis of the wave functions. We find that the singleparticle tunneling shifts between the probability of double occupancy in the same well and that of single occupancy in different wells.  [Show abstract] [Hide abstract]
ABSTRACT: We present a variational study of pseudospin $1/2$ Bose gases in a harmonic trap with weak 3D spinorbit coupling of $\bmsigma\cdot\mathbf{p}$ type. This spinorbit coupling mixes states with different parities, which inspires us to approximate the single particle state with the eigenstates of the total angular momentum, i.e. superposition of harmonic $s$wave and $p$wave states. As the time reversal symmetry is protected by twobody interaction, we set the variational order parameter as the combination of two mutually time reversal symmetric eigenstates of the total angular momentum. The variational results essentially reproduce the 3D skyrmionlike ground state recently identified by Kawakami {\it et al.}. We show that these skyrmionlike ground states emerging in this model are primarily caused by $p$ wave spatial mode involving in the variational order parameter that drives two spin components spatially separated. We find the ground state of this system falls into two phases with different density distribution symmetries depending on the relative magnitude of intraspecies and interspecies interaction: Phase I has parity symmetric and axisymmetric density distributions, while Phase II is featured with special joint symmetries of discrete rotational and time reversal symmetry. With the increasing interaction strength the transition occurs between two phases with distinct density distributions, while the topological 3D skyrmionlike spin texture is symmetry protected.  [Show abstract] [Hide abstract]
ABSTRACT: We propose to experimentally realize an odd parity eigenstate $\left\vert b\right\rangle $ of two atoms in the double well. The occupation probability of this state shows evident dependence on the interaction, distinct from the result of twomode model adopted in the Heidelberg experiment. The tunneling dynamics of two atoms starting from the $NOON$ state with infinite barrier height can be derived from the exactly solved model of $\delta $barrier split double well based on a Bethe ansatz type hypothesis of the wave functions. We find that the single particle tunneling transfer the probabilities between double occupancy and single occupancy of each well.  [Show abstract] [Hide abstract]
ABSTRACT: We investigate continuoustime quantum walks of two indistinguishable anyons in onedimensional lattices with both onsite and nearestneighbor interactions based on the fractional JordanWigner transformation. It is shown that the twobody correlations in position space are symmetric about the initial sites of two quantum walkers in the Bose limit ($\chi=0$ ) and Fermi limit ( $\chi=1$), while in momentum space this happens only in the Bose limit. An interesting asymmetry arises in the correlation for most cases with the statistical parameter $\chi$ varying in between. It turns out that the origin of this asymmetry comes from the fractional statistics that anyons obey. On the other hand, the twobody correlations of hardcore anyons in position spaceshow uniform behaviors from antibunching to cowalking regardless of the statistical parameter. The momentum correlations in the case of strong interaction undergo a smooth process of two stripes smoothly merging into a single one, i.e. the evolution of fermions into hardcore bosons.  [Show abstract] [Hide abstract]
ABSTRACT: We investigate the macroscopic quantum coherence of a spin1 Rb condensate confined in an anisotropic potential. Under the singlemode approximation, we show that the system can be modeled as a biaxial quantum magnet due to the interplay between the magnetic dipoledipole interaction and the anisotropic potential. By applying a magnetic field along the hardaxis, we show that the tunneling splitting oscillates as a function of the field strength. We also propose an experimental scheme to detect the oscillatory behavior of the tunneling splitting by employing the LandauZener tunneling.  [Show abstract] [Hide abstract]
ABSTRACT: We investigate the stability and the free expansion of a trapped dipolar Fermi gas. We show that stabilizing the system relying on tuning the trap geometry is generally inefficient. We further show that the expanded density profile always gets stretched along the attractive direction of dipolar interaction. We also point out that by switching off the dipolar interaction simultaneously with the trapping potential, the deformation of momentum distribution can be directly observed. Comment: 5 pages, 5 figures
Publication Stats
27  Citations  
16.85  Total Impact Points  
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Institutions

20072015

Shanxi University
Yangkü, Shanxi Sheng, China
