Quasi-spin projection in an exactly soluble model

D. Galetti, B. M. Pimentel, C. L. Lima

S. Y. Chu, Eugene R. Marshalek, Peter A. Ring +2 more

The exactly soluble R(8) model of Krumlinde and Szyma\ifmmode \acute{n}\else \'{n}\fi{}ski is used as a testing ground for three many-body methods applied to the yrast band: (i) the self-consistent cranking model, (ii) self-consistent cranking plus random-phase approximation, and (iii) variation after projection of particle number. All three methods agree very well with exact results outside of the critical region. The behavior in the critical region is examined in detail.NUCLEAR STRUCTURE Many-body methods, solvable model, high-spin states.

Nikolai Nikolaevich Bogoliubov, A.S. Shumovsky

Xue-Yang Song, Yi‐Zhuang You, Leon Balents

We investigate the generic features of the low energy dynamical spin structure factor of the Kitaev honeycomb quantum spin liquid perturbed away from its exact soluble limit by generic symmetry-allowed exchange couplings. We find that the spin gap persists in the Kitaev-Heisenberg model, but generally vanishes provided more generic symmetry-allowed interactions exist. We formulate the generic expansion of the spin operator in terms of fractionalized Majorana fermion operators according to the symmetry enriched topological order of the Kitaev spin liquid, described by its projective symmetry group. The dynamical spin structure factor displays power-law scaling bounded by Dirac cones in the vicinity of the Γ, K, and K^{'} points of the Brillouin zone, rather than the spin gap found for the exactly soluble point.

H. Y. Shik, Y.Q. Li, H. Q. Lin

N. N. Bogolyubov