Abstract

We use symmetry to find the mean-field states that can arise at a continuous transition from the normal phase in a two-dimensional itinerant Heisenberg model on a square lattice with unit cell a\ifmmode\times\else\texttimes\fi{}a. All states consistent with a \ensuremath{\surd}2 a\ifmmode\times\else\texttimes\fi{} \ensuremath{\surd}2 a unit cell for both ferromagnetic and antiferromagnetic couplings of the exchange constant are considered. A sublattice SU(2) symmetry is used to map between particle-hole and particle-particle states, charge and singlet-pairing states, and spin and triplet-pairing states. We calculate the critical temperatures for these states and find, at weak coupling, a spin-current state that has a higher critical temperature than the ferromagnetic state.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.