skip to main content

DOE PAGESDOE PAGES

Title: Designing Quantum Spin-Orbital Liquids in Artificial Mott Insulators

Quantum spin-orbital liquids are elusive strongly correlated states of matter that emerge from quantum frustration between spin and orbital degrees of freedom. A promising route towards the observation of those states is the creation of artificial Mott insulators where antiferromagnetic correlations between spins and orbitals can be designed. We show that Coulomb impurity lattices on the surface of gapped honeycomb substrates, such as graphene on SiC, can be used to simulate SU(4) symmetric spin-orbital lattice models. We exploit the property that massive Dirac fermions form mid-gap bound states with spin and valley degeneracies in the vicinity of a Coulomb impurity. Due to electronic repulsion, the antiferromagnetic correlations of the impurity lattice are driven by a super-exchange interaction with SU(4) symmetry, which emerges from the bound states degeneracy at quarter filling. We propose that quantum spin-orbital liquids can be engineered in artificially designed solid-state systems at vastly higher temperatures than achievable in optical lattices with cold atoms. Lastly, we discuss the experimental setup and possible scenarios for candidate quantum spin-liquids in Coulomb impurity lattices of various geometries.
Authors:
 [1] ;  [2] ;  [1]
  1. Univ. of Oklahoma, Norman, OK (United States). Dept. of Physics and Astronomy
  2. Univ. of Vermont, Burlington, VT (United States). Dept. of Physics
Publication Date:
OSTI Identifier:
1326663
Grant/Contract Number:
FG02-08ER46512; NMR-1352604
Type:
Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 6; Journal ID: ISSN 2045-2322
Publisher:
Nature Publishing Group
Research Org:
Boston Univ
Sponsoring Org:
USDOE; NSF
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS