Relaxation operator for quasiparticles in a solid
arXiv:2009.09021 · doi:10.1103/PhysRevB.102.235103
Abstract
Popular models of the phenomenological relaxation operators that are widely used in the master equation formalism for open condensed-matter systems have significant flaws ranging from limited applicability to violation of fundamental physical principles. We propose a relatively simple universal model of the relaxation operator which is free from these flaws, has a correct static limit, correct direct-current limit in a uniform electric field, includes both interband and intraband transitions, and is valid for an arbitrary dispersion of quasiparticles in a solid. We use the proposed operator to generalize the Lindhard formula and derive explicit expressions for the relaxation operator for Dirac materials with an unconventional energy spectrum of quasiparticles, such as graphene and Weyl semimetals. We compare the linear susceptibility spectra for graphene obtained with different relaxation models and show that the proposed relaxation operator leads to physically meaningful behavior of the susceptibility at low frequencies whereas the existing models become completely invalid.
arXiv comment37 pages, 3 figures
References in corpus (14)
- Dirac Fermions in Solids - from High Tc cuprates and Graphene to Topological Insulators and Weyl Semimetals
- 3D massless Kane fermions observed in a zinc-blende crystal
- Efficient nonlinear generation of THz plasmons in graphene and topological insulators
- Superradiant Decay of Cyclotron Resonance of Two-Dimensional Electron Gases
- The Rotating-Wave Approximation: Consistency and Applicability from an Open Quantum System Analysis
- Second-order nonlinear optical response of graphene
- Microscopic mechanism for transient population inversion and optical gain in graphene
- Optical properties and electromagnetic modes of Weyl semimetals
- Relaxation of an Electron System : Conserving Approximation
- Extending the validity range of quantum optical master equations
- Conservation law of operator current in open quantum systems
- Continuous wave lasing between Landau levels in graphene
- Extreme anisotropy and gyrotropy of surface polaritons in Weyl semimetals
- Difference frequency generation of surface plasmon-polaritons in Landau quantized graphene