General principles for the non-equilibrium relaxation of populations in quantum materials

Abstract

We examine the problem of how excited populations of electrons relax after they have been excited by a pump. We include three of the most important relaxation processes: (i) impurity scattering; (ii) Coulomb scattering; and (iii) electron-phonon scattering. The relaxation of an excited population of electrons is one of the most fundamental processes measured in pump/probe experiments, but its interpretation remains under debate. We show how several common assumptions about non-equilibrium relaxation that are pervasive in the field may not hold under quite general conditions. The analysis shows that non-equilibrium relaxation is more complex than previously thought, but it yields to recently developed theoretical methods in non-equilibrium theory. In this work, we show how one can use many-body theory to properly interpret and analyze these complex systems. We focus much of the discussion on implications of these results for experiment.

13 pages, 10 figures

References in corpus (4)

• Thermalization and its mechanism for generic isolated quantum systems
• Theoretical description of time-resolved photoemission spectroscopy: application to pump-probe experiments
• Interaction quench in the Holstein model: Thermalization crossover from electron- to phonon-dominated relaxation
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• Low rank compression in the numerical solution of the nonequilibrium Dyson equation
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• Nonequilibrium Electron Dynamics In Pump-Probe Spectroscopy: Role Of Excited Phonon Populations
• Coherent Modulation of Quasiparticle Scattering Rates in a Photoexcited Charge-Density-Wave System
• Quantum Interference Control of Localized Carrier Distributions in the Brillouin Zone
• Ultrafast Momentum-resolved Hot Electron Dynamics in the Two-dimensional Topological Insulator Bismuthene
• Boltzmann relaxation dynamics of strongly interacting spinless fermions on a lattice
• Relaxation timescales and electron-phonon coupling in optically-pumped YBa${}_2$Cu${}_3$O${}_{6+x}$ revealed by time-resolved Raman scattering
• Energy flow during relaxation in an electron-phonon system with multiple modes: A nonequilibrium Green's function study
• Nonequilibrium phase transition in a driven-dissipative quantum antiferromagnet
• Relaxation of photo-excited hot carriers beyond multi-temperature models: General theory description verified by experiments on Pb/Si(111)
• Detecting isotropic density and nematic fluctuations using ultrafast coherent phonon spectroscopy