Vortices in the Su(n) X Su(n) Spin Systems in Two Dimensions.

John Schliemann, Franz G. Mertens

Emi Yukawa, Masahito Ueda

A generalized Mermin-Ho relation for a spin-1 Bose-Einstein condensate is derived, which is applicable to vortices regardless of the symmetry and spin polarization of the order parameter. The obtained relation implies an su(3) mass-current circulation and two classes of vortices corresponding to two different su(2) subalgebras.

Peng Li, Shun-Qing Shen

A class of the symmetrically frustrated SU( N ) models is constructed for quantum magnets based on the generators of the SU( N ) group. The total Hamiltonian lacks SU( N ) symmetry. A mean field theory in the quasi-particle representation is developed for spin liquid states. Numerical solutions in two dimensions indicate that the ground states are gapless and the quasi-particles are Dirac particles. The mechanism may be helpful in exploring the spin liquid phases in the spin-1 bilinear-biquadratic model and the spin–orbital model in higher dimensions.

Michele Caselle, Ferdinando Gliozzi, R. Megna

Л. П. Рапопорт, A.G. Krylovetskii

Emi Yukawa

The Mermin-Ho relation expresses the vorticity of a coreless su(2) vortex in terms of the spin-1 or l vector which characterizes fully polarized superfluid textures. We generalize it to an su(N) vortex which is applicable to arbitrarily polarized superfluid textures with higher spin or angular momentum. The obtained relation is expressed in terms of the mean-field generators and their structure factors.