Birefringent breakup of Dirac fermions on a square optical lattice

Journal Article · Sun May 15 00:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.83.053636· OSTI ID:21546849

Kennett, Malcolm P; Komeilizadeh, Nazanin; Kaveh, Kamran; Smith, Peter M ^[1]

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1. Physics Department, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, V5A 1S6 (Canada)

We introduce a lattice model for fermions in a spatially periodic magnetic field that also has spatially periodic hopping amplitudes. We discuss how this model might be realized with cold atoms in an artificial magnetic field on a square optical lattice. When there is an average flux of half a flux quantum per plaquette, the spectrum of low-energy excitations can be described by massless Dirac fermions in which the usually doubly degenerate Dirac cones split into cones with different ''speeds of light.'' These gapless birefringent Dirac fermions arise because of broken chiral symmetry in the kinetic energy term of the effective low-energy Hamiltonian. We characterize the effects of various perturbations to the low-energy spectrum, including staggered potentials, interactions, and domain-wall topological defects.

• OSTI ID: 21546849
• Journal Information: Physical Review. A, Vol. 83, Issue 5; Other Information: DOI: 10.1103/PhysRevA.83.053636; (c) 2011 American Institute of Physics; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMS
BIREFRINGENCE
CHIRAL SYMMETRY
DISTURBANCES
ENERGY SPECTRA
EXCITATION
FERMIONS
HAMILTONIANS
INTERACTIONS
KINETIC ENERGY
LATTICE PARAMETERS
LIGHT CONE
MAGNETIC FIELDS
PERIODICITY
POTENTIALS
TOPOLOGY
ENERGY
ENERGY-LEVEL TRANSITIONS
MATHEMATICAL OPERATORS
MATHEMATICS
QUANTUM OPERATORS
REFRACTION
SPACE-TIME
SPECTRA
SYMMETRY
VARIATIONS