A generalized Stoner criterion and versatile spin ordering in two-dimensional spin-orbit coupled electron systems
arXiv:1708.01971 · doi:10.1103/PhysRevB.96.235425
Abstract
Spin-orbit coupling is a single-particle phenomenon known to generate topological order, and electron-electron interactions cause ordered many-body phases to exist. The rich interplay of these two mechanisms is present in a broad range of materials, and has been the subject of considerable ongoing research and controversy. Here we demonstrate that interacting two-dimensional electron systems with strong spin-orbit coupling exhibit a variety of time reversal symmetry breaking phases with unconventional spin alignment. We first prove that a Stoner-type criterion can be formulated for the spin polarization response to an electric field, which predicts that the spin polarization susceptibility diverges at a certain value of the electron-electron interaction strength. The divergence indicates the possibility of unconventional ferromagnetic phases even in the absence of any applied electric or magnetic field. This leads us, in the second part of this work, to study interacting Rashba spin-orbit coupled semiconductors in equilibrium in the Hartree-Fock approximation as a generic minimal model. Using classical Monte-Carlo simulations we construct the complete phase diagram of the system as a function of density and spin-orbit coupling strength. It includes both an out-of-plane spin polarized phase and in-plane spin-polarized phases with shifted Fermi surfaces and rich spin textures, reminiscent of the Pomeranchuk instability, as well as two different Fermi-liquid phases having one and two Fermi surfaces, respectively, which are separated by a Lifshitz transition. We discuss possibilities for experimental observation and useful application of these novel phases, especially in the context of electric-field-controlled macroscopic spin polarizations.
17 pages, 5 figures
References in corpus (24)
- Quantum Spin Hall Insulator State in HgTe Quantum Wells
- Quantized Anomalous Hall Effect in Magnetic Topological Insulators
- Theory of ferromagnetic (III,Mn)V semiconductors
- An Exact SU(2) Symmetry and Persistent Spin Helix in a Spin-Orbit Coupled System
- Emergence of the persistent spin helix in semiconductor quantum wells
- Spin current and polarization in impure 2D electron systems with spin-orbit coupling
- Current induced electron spin polarization in strained semiconductors
- Phase Diagram of the Low-Density Two-Dimensional Homogeneous Electron Gas
- Parity-breaking phases of spin-orbit-coupled metals with gyrotropic, ferroelectric and multipolar orders
- Functional Keldysh Theory of Spin Torques
- Non-Abelian gauge fields in the gradient expansion: generalized Boltzmann and Eilenberger equations
- Chiral spin resonance and spin-Hall conductivity in the presence of the electron-electron interactions
- Perpendicular magnetic anisotropy of two-dimensional Rashba ferromagnets
- On the nature of steady states of spin distributions in the presence of spin-orbit interactions
- Weak momentum scattering and the conductivity of graphene
- Ferromagnetic and Nematic Non-Fermi Liquids in Spin-Orbit Coupled Two-Dimensional Fermi Gases
- Nematic domains and resistivity in an itinerant metamagnet coupled to a lattice
- Exchange energy and generalized polarization in the presence of spin-orbit coupling in two dimensions
- Self-masking of spontaneous symmetry breaking in layer materials
- Optical Conductivity of a Two-Dimensional Electron Liquid with Spin-Orbit Interaction
- Hartree-Fock ground state of the two-dimensional electron gas with Rashba spin-orbit interaction
- Pomeranchuk instability: symmetry breaking and experimental signatures
- Polarization of a quasi two-dimensional repulsive Fermi gas with Rashba spin-orbit coupling: a variational study
- Evidence of breakdown of the spin symmetry in diluted 2D electron gases