2008/06/30 by Fa Wang, Ashvin Vishwanath
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.80.064413
published as Phys. Rev. B 80, 064413 (2009) · 9 pages, 4 figures, 3 tables, published version
openalex publication_date 2009/08/19 · arxiv created 2009/08/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We argue for the existence of a liquid ground state in a class of square lattice models of orbitally degenerate insulators. Starting with the SU(4)-symmetric Kugel-Khomskii model, we utilize a Majorana Fermion representation of spin-orbital operators to access unusual phases. Variational wave functions of candidate liquid phases are thus obtained, whose properties are evaluated using variational Monte Carlo. These states are disordered and are found to have excellent energetics and ground state overlap (>40%) when compared with exact diagonalization on 16-site clusters. We conclude that these are spin-orbital liquid ground states with emergent nodal fermions and Z2 gauge fields. Connections to spin-3/2 cold-atom systems and properties in the absence of SU(4) symmetry are briefly discussed.