Theory of Coulomb driven nematicity in a multi-valley two-dimensional electron gas

Abstract

The properties of a two-dimensional electron gas (2DEG) in a semiconductor host with two valleys related by an underlying $C_4$ rotational symmetry are studied using Hartree-Fock (HF) and various other many-body approaches. A familiar artifact of the HF approach is a degeneracy between the valley polarized - ``Ising nematic'' - and spin polarized - ferromagnetic - phases, which is inconsistent with recent variational Monte Carlo (VMC) results. Correlation effects, computed either within the random phase approximation (RPA) or the T-matrix approximation, enhance the valley susceptibility relative to the spin susceptibility. Extrapolating the results to finite interaction strength, we find a direct first-order transition from a symmetry-unbroken state to a spin unpolarized Ising nematic fluid with full valley polarization, in qualitative agreement with VMC. The RPA results are also reminiscent of experiments on the corresponding 2DEG in AlAs heterostructures.

arXiv comment6 + 25 pages, 12 figures

References in corpus (18)

• How to detect fluctuating order in the high-temperature superconductors
• Altermagnetism: spin-momentum locked phase protected by non-relativistic symmetries
• Quantum Theory of a Nematic Fermi Fluid
• The Hubbard Model
• Valley susceptibility of an interacting two-dimensional electron system
• Two-dimensional electrons occupying multiple valleys in AlAs
• Inter-valley coherent order and isospin fluctuation mediated superconductivity in rhombohedral trilayer graphene
• Imaging inter-valley coherent order in magic-angle twisted trilayer graphene
• Universal phase structure of dilute Bose gases with Rashba spin-orbit coupling
• Electronic Liquid Crystalline Phases in a Spin-Orbit Coupled Two-Dimensional Electron Gas
• Intervalley coherence and intrinsic spin-orbit coupling in rhombohedral trilayer graphene
• Observation of spontaneous valley polarization of itinerant electrons
• Quantum criticality of a Fermi gas with a spherical dispersion minimum
• Ferromagnetic and Nematic Non-Fermi Liquids in Spin-Orbit Coupled Two-Dimensional Fermi Gases
• Correlation energy in a spin polarized two dimensional electron liquid in the high density limit
• Exact energy of the spin-polarized two-dimensional electron gas at high density
• Nematic metal in a multi-valley electron gas: Variational Monte Carlo analysis and application to AlAs
• Competition of Exchange and Correlation Energies in Two-Dimensional $N$-component Electron Gas Ferromagnetism

Cited by in corpus (2)

• Quantum Monte Carlo study of the quasiparticle effective mass of the two-dimensional uniform electron liquid
• False Vacuum Decay in Flat-Band Ferromagnets: Role of Quantum Geometry and Chiral Edge States