Anomalous Spin Precession under a Geometrical Torque

Area of Science:

• Condensed matter physics
• Quantum mechanics
• Spintronics

Background:

• Spin dynamics in magnetic fields are typically governed by precession and relaxation.
• Interactions between spins and conduction electrons in Fermi seas are crucial for understanding material properties.

Purpose of the Study:

• To investigate the real-time dynamics of a spin coupled to a Fermi sea of conduction electrons.
• To demonstrate and explain anomalous spin precession phenomena.

Main Methods:

• Theoretical modeling of spin dynamics under magnetic fields.
• Analysis of spin-electron coupling within a Fermi sea.
• Investigating the adiabatic limit of electronic motion following spin dynamics.

Main Results:

• Observed anomalous spin precession with frequencies higher than the Larmor frequency.
• Demonstrated inverted spin orientation in the adiabatic limit.
• Identified a geometrical torque arising from finite spin Berry curvature as the cause.

Conclusions:

• The study reveals anomalous spin precession driven by magnetic fields and coupled to conduction electrons.
• Geometric torque from spin Berry curvature explains the observed anomalous dynamics.
• Findings contribute to understanding spin behavior in correlated electron systems.