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Nonlinear Hall Effect from Long-Lived Valley-Polarizing Relaxons
Jae-Mo Lihm1, Cheol-Hwan Park1
1Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea; Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea; and Center for Theoretical Physics, Seoul National University, Seoul 08826, Korea.
Physical Review Letters
|March 22, 2024
Summary
Researchers found a 60% enhancement in the nonlinear Hall effect of n-doped GeTe, challenging the Berry curvature dipole theory. Long-lived valley polarization due to electron-phonon scattering explains this novel frequency-dependent phenomenon.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Transport
Background:
- The nonlinear Hall effect is often explained by the Berry curvature dipole in momentum space.
- This interpretation has been widely adopted in condensed matter physics.
Purpose of the Study:
- To investigate the nonlinear Hall effect in n-doped Germanium Telluride (GeTe).
- To explore deviations from the Berry curvature dipole model and identify underlying mechanisms.
Main Methods:
- Utilizing ab initio Boltzmann transport equations for theoretical calculations.
- Analyzing electron-phonon scattering and its impact on electron distribution.
Main Results:
- Observed a 60% enhancement in the nonlinear Hall effect of n-doped GeTe.
- Identified a noticeable frequency dependence, differing from Berry curvature dipole predictions.
- Attributed the discrepancies to long-lived valley polarization in the electron distribution.
Conclusions:
- The Berry curvature dipole model is insufficient to explain the observed nonlinear Hall effect in n-doped GeTe.
- Electron-phonon scattering induces valley polarization, significantly influencing transport properties.
- Experimental verification of these findings is crucial.
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