Nonexponential quasiparticle decay and phase relaxation in low-dimensional conductors

Area of Science:

• Condensed matter physics
• Disordered conductors
• Quantum mechanics

Background:

• Understanding charge transport and relaxation mechanisms in disordered materials is crucial.
• Previous models often assumed exponential decay for quasiparticle and phase relaxation.

Purpose of the Study:

• To investigate the nature of quasiparticle decay and phase relaxation in low-dimensional disordered conductors.
• To determine the temperature dependence of inelastic scattering time.

Main Methods:

• Modified derivation of the Fermi golden rule.
• Analysis of quasiparticle decay and phase relaxation dynamics at small times.

Main Results:

• Quasiparticle decay and phase relaxation are non-exponential in low-dimensional disordered conductors.
• In quasi-one-dimensional systems, both processes exhibit a characteristic time dependence of e(-(t/τ_in)^3/2).
• The inelastic time (τ_in) shows a power-law dependence on temperature: τ_in ∝ T^-2/3.

Conclusions:

• The findings challenge conventional assumptions of exponential relaxation in disordered systems.
• A modified Fermi golden rule explains the non-exponential quasiparticle decay.
• The results suggest an unusual distribution of relaxation times in these materials.