Modified transverse Ising model for the dielectric properties of SrTiO films and interfaces
arXiv:1905.07430 · doi:10.1088/1361-648X/ab4fa7
Abstract
The transverse Ising model (TIM), with pseudospins representing the lattice polarization, is often used as a simple description of ferroelectric materials. However, we demonstrate that the TIM, as it is usually formulated, provides an incorrect description of SrTiO films and interfaces because of its inadequate treatment of spatial inhomogeneity. We correct this deficiency by adding a pseudospin anisotropy to the model. We demonstrate the physical need for this term by comparison of the TIM to a typical Landau-Ginzburg-Devonshire model. We then demonstrate the physical consequences of the modification for two model systems: a ferroelectric thin film, and a metallic LaAlO/SrTiO interface. We show that, in both cases, the modified TIM has a substantially different polarization profile than the conventional TIM. In particular, at low temperatures the formation of quantized states at LaAlO/SrTiO interfaces only occurs in the modified TIM.
arXiv comment22 pages, 8 figures
References in corpus (22)
- Magnetic effects at the interface between nonmagnetic oxides
- Electric Field Control of the LaAlO/SrTiO Interface Ground State
- Tunable Rashba spin-orbit interaction at oxide interfaces
- Coexistence of superconductivity and ferromagnetism in two dimensions
- Tuning spin-orbit coupling and superconductivity at the SrTiO3/LaAlO3 interface: a magneto-transport study
- A Universal Critical Density Underlying the Physics of Electrons at the LaAlO3/SrTiO3 Interface
- A ferroelectric quantum phase transition inside the superconducting dome of SrCaTiO
- Quantum critical origin of the superconducting dome in SrTiO
- Towards two-dimensional metallic behavior at LaAlO3/SrTiO3 interfaces
- Theory of the SrTiO3 Surface State Two-Dimensional Electron Gas
- First-principles modeling of electrostatically doped perovskite systems
- Dynamical response and confinement of the electrons at the LaAlO3/SrTiO3 interface
- Metal-Insulator Transition of the LaAlO3-SrTiO3 Interface Electron System
- Charge density distribution and optical response of the LaAlO3/SrTiO3 interface
- Strain and ferroelectric soft mode induced superconductivity in strontium titanate
- Tuning Rashba spin-orbit coupling at LaAlO3/SrTiO3 interfaces by band filling
- Anisotropic, multi-carrier transport at the (111) LaAlO/SrTiO interface
- Magnetic and nematic orders of the 2DEG at oxide (111) surfaces and interfaces
- Influence of the ferroelectric quantum critical point on SrTiO interfaces
- Temperature-Dependent Band Structure of SrTiO Interfaces
- Possible Flexoelectric Origin of the Lifshitz Transition in LaAlO/SrTiO Interfaces
- Anisotropic Magnetoresistance in Multiband Systems: 2DEGs and Polar Metals at Oxide Interfaces