CPM Seminar

Electronic Liquid Crystalline Phases in a Spin-Orbit Coupled Two-Dimensional Electron Gas

Erez Berg

Harvard University

We argue that the ground state of a two-dimensional electron gas with Rashba spin-orbit coupling realizes one of several possible liquid crystalline or Wigner crystalline phases in the low-density limit, even for short-range repulsive electron-electron interactions (which decay with distance with a power larger than 2). Depending on specifics of the interactions, preferred ground-states include an anisotropic Wigner crystal with an increasingly anisotropic unit cell as the density decreases, a striped or electron smectic phase, and a ferromagnetic phase which strongly breaks the lattice point-group symmetry, i.e. exhibits nematic order. Melting of the anisotropic Wigner crystal or the smectic phase by thermal or quantum fluctuations can gives rise to a non-magnetic nematic phase which preserves time-reversal symmetry.