Spin-relaxation time in materials with broken inversion symmetry and large spin-orbit coupling

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Mechanics

Background:

• Spin-orbit coupling (SOC) is crucial in materials lacking spatial inversion symmetry.
• The D'yakonov-Perel' (DP) mechanism typically describes spin relaxation in such systems.
• Zincblende structures and heterostructures with electric fields exhibit significant SOC.

Purpose of the Study:

• To investigate spin-relaxation time in materials with large spin-orbit coupling.
• To compare and validate different theoretical approaches for spin relaxation.
• To identify novel spin-relaxation regimes and their characteristics.

Main Methods:

• Combined Monte Carlo simulations for time evolution of electron spins.
• Diagrammatic calculations utilizing the spin-diffusion propagator.
• Quasiparticle dynamics simulation in the presence of spin-orbit magnetic fields.

Main Results:

• Achieved parameter-free quantitative agreement between Monte Carlo and diagrammatic methods.
• Validated the conventional D'yakonov-Perel' mechanism in the appropriate limit.
• Identified two new spin-relaxation regimes: strongly non-exponential relaxation and relaxation matching momentum relaxation.

Conclusions:

• The study confirms the robustness of theoretical approaches for spin relaxation.
• New insights into spin relaxation dynamics under varying SOC strength and momentum relaxation rates were gained.
• An analogy between spin-relaxation theory and NMR motional narrowing was highlighted.