arXiv subjects

Su Yi

Publications and source records attributed to Su Yi.

57 records · Page 4Linked to original sources

arXiv2008

Dipolar spinor Bose-Einstein condensates

Under many circumstances, the only important two-body interaction between atoms in ultracold dilute atomic vapors is the short-ranged isotropic s-wave collision. Recent studies have shown, however, that situations may arise where the dipolar interaction between atomic magnetic or electric dipole moments can play a significant role. The long-range anisotropic nature of the dipolar interaction greatly enriches the static and dynamic properties of ultracold atoms. In the case of dipolar spinor condensates, the interplay between the dipolar interaction and the spin exchange interaction may lead to nontrivial spin textures. Here we pay particular attention to the spin vortex state that is analogous to the magnetic vortex found in thin magnetic films.

cond-mat.other↗

arXiv2004

Bose-Einstein condensation of trapped interacting spin-1 atoms

We investigate Bose-Einstein condensation of trapped spin-1 atoms with ferromagnetic or antiferromagnetic two-body contact interactions. We adopt the mean field theory and develop a Hartree-Fock-Popov type approximation in terms of a semiclassical two-fluid model. For antiferromagnetic interactions, our study reveals double condensations as atoms in the $|m_F=0>$ state never seem to condense under the constraints of both the conservation of total atom number $N$ and magnetization $M$. For ferromagnetic interactions, however, triple condensations can occur. Our results can be conveniently understood in terms of the interplay of three factors: (anti) ferromagnetic atom-atom interactions, $M$ conservation, and the miscibilities between and among different condensed components.

cond-mat.stat-mech↗

arXiv2003

Mean field ground state of a spin-1 condensate in a magnetic field

We revisit the topic of the mean field ground state of a spin-1 atomic condensate inside a uniform magnetic field ($B$) under the constraints that both the total number of atoms ($N$) and the magnetization ($\cal M$) are conserved. In the presence of an internal state (spin component) independent trap, we also investigate the dependence of the so-called single spatial mode approximation (SMA) on the magnitude of the magnetic field and ${\cal M}$. Our result indicate that the quadratic Zeeman effect is an important factor in balancing the mean field energy from elastic atom-atom collisions that are known to conserve both $N$ and $\cal M$.

cond-mat.soft↗