Zhentao Wang

Spin Ferroquadrupolar Order in the Nematic Phase of FeSe

We provide evidence that spin ferroquadrupolar (FQ) order is the likely ground state in the nonmagnetic nematic phase of stoichiometric FeSe. By studying the variational mean-field phase diagram of a bilinear-biquadratic Heisenberg model up to the 2nd nearest neighbor, we find the FQ phase in close proximity to the columnar antiferromagnet commonly realized in iron-based superconductors; the stability of the FQ phase is further verified by the density matrix renormalization group. The dynamical spin structure factor in the FQ state is calculated with flavor-wave theory, which yields a qualitatively consistent result with inelastic neutron scattering experiments on FeSe at both low and high energies. We verify that FQ can coexist with C_{4} breaking environments in the mean-field calculation, and further discuss the possibility that quantum fluctuations in FQ act as a source of nematicity.

Chiral liquid phase of simple quantum magnets

We study a

Orbital nematic order and interplay with magnetism in the two-orbital Hubbard model

T=0

Spin dynamics of a J 1-J 2-K model for the paramagnetic phase of iron pnictides

quantum phase transition between a quantum paramagnetic state and a magnetically ordered state for a spin

Three-Dimensional Crystallization of Vortex Strings in Frustrated Quantum Magnets.

S=1

Resistivity Minimum in Highly Frustrated Itinerant Magnets

XXZ Heisenberg antiferromagnet on a two-dimensional triangular lattice. The transition is induced by an easy plane single-ion anisotropy

Semiclassical dynamics of spin density waves

D

Gradient-based stochastic estimation of the density matrix

. At the mean-field level, the system undergoes a direct transition at a critical

Erratum: Spin Ferroquadrupolar Order in the Nematic Phase of FeSe [Phys. Rev. Lett. 116 , 247203 (2016)]

D = D_c

Principal Chiral Model in Correlated Electron Systems.

between a paramagnetic state at