Universal transparency and fine band structure near the Dirac point in HgTe quantum wells
arXiv:2504.15877 · doi:10.1103/PhysRevB.106.045302
Abstract
Spin-orbit coupling in thin HgTe quantum wells results in a relativistic-like electron band structure, making it a versatile solid state platform to observe and control non-trivial electrodynamic phenomena. Here we report an observation of universal terahertz (THz) transparency determined by fine-structure constant in 6.5 nm-thick HgTe layer, close to the critical thickness separating phases with topologically different electronic band structure. Using THz spectroscopy in magnetic field we obtain direct evidence of asymmetric spin splitting of the Dirac cone. This particle-hole asymmetry facilitates optical control of edge spin currents in the quantum wells.
6 pages, 2 figures
References in corpus (35)
- Universal Dynamic Conductivity and Quantized Visible Opacity of Suspended Graphene
- Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
- Weyl and Dirac Semimetals in Three Dimensional Solids
- Measurement of the Optical Conductivity of Graphene
- Quantum Spin Hall Effect in Inverted Type II Semiconductors
- Quantized Faraday and Kerr rotation and axion electrodynamics of a 3D topological insulator
- Topological Superconductivity in a Phase-Controlled Josephson Junction
- Single valley Dirac fermions in zero-gap HgTe quantum wells
- Colloquium: Graphene spectroscopy
- Observation of the universal magnetoelectric effect in a 3D topological insulator
- Interacting topological edge channels
- Split Dirac cones in HgTe/CdTe quantum wells due to symmetry-enforced level anticrossing at interfaces
- Giant spin-polarized current in a Dirac fermion system at cyclotron resonance
- Fine structure of "zero-mode" Landau levels in HgTe/HgCdTe quantum wells
- Temperature-induced topological phase transition in HgTe quantum wells
- Suppressed Auger scattering and tunable light emission of Landau-quantized massless Kane electrons
- Spin-orbit splitting of valence and conduction bands in HgTe quantum wells near the Dirac point
- Universal Faraday rotation in HgTe wells with critical thickness
- Photogalvanic effect in HgTe/CdTe topological insulator due to edge-bulk optical transitions
- Topological protection brought to light by the time-reversal symmetry breaking
- High-frequency nonlinear transport and photogalvanic effects in two-dimensional topological insulators
- The transparency of graphene and other direct-gap two dimensional materials
- Interplay of Dirac nodes and Volkov-Pankratov surface states in compressively strained HgTe
- Edge photogalvanic effect caused by optical alignment of carrier momenta in 2D Dirac materials
- Hole transport and valence band dispersion law in a HgTe quantum well with normal energy spectrum
- Band structure of a HgTe-based three-dimensional topological insulator
- Terahertz properties of Dirac fermions in HgTe films with optical doping
- High-frequency breakdown of the integer QHE in GaAs/AlGaAs heterojunctions
- Linearity of the edge states energy spectrum in the 2D topological insulator
- Optical properties of helical edge channels in zinc-blende-type topological insulators: Selection rules, circular and linear dichroism, circular and linear photocurrents
- Giant Electron-hole Charging Energy Asymmetry in Ultra-short Carbon Nanotubes
- Electron-hole scattering limited transport of Dirac fermions in a topological insulator
- Edge absorption and pure spin current in 2D topological insulator in the Volkov-Pankratov model
- Density of states measurements for heavy subband of holes in HgTe quantum wells
- Impact ionization induced by terahertz radiation in HgTe quantum wells of critical thickness