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Quantum metric third-order nonlinear Hall effect in a non-centrosymmetric ferromagnet
Hao Yu1,2, Xinjie Li2,3, Ya-Qing Bie2,3
1Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, Nanotechnology Research Center, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, PR China.
Nature Communications
|August 18, 2025
Summary
Researchers discovered a third-order nonlinear Hall effect in Fe5GeTe2 at room temperature, driven by quantum metrics. This finding advances quantum spintronic devices with higher conductivity and efficiency.
Area of Science:
- Condensed Matter Physics
- Quantum Geometry
- Spintronics
Background:
- Berry curvature (imaginary part of quantum geometry) influences nonlinear Hall effects in Weyl semimetals.
- Previous research on quantum metrics (real part of quantum geometry) focused on second-order nonlinear Hall transport at low temperatures.
Purpose of the Study:
- Investigate the influence of quantum metrics on higher-order nonlinear Hall transport.
- Explore the third-order nonlinear Hall effect in ferromagnetic materials at room temperature.
Main Methods:
- Utilized non-centrosymmetric ferromagnetic Fe5GeTe2 as the material.
- Observed and confirmed the third-order nonlinear Hall effect through distinct scaling behaviors and electron spin state dependence.
- Extended second-order quantum metric dipole scaling to derive a third-order equation.
Main Results:
- Demonstrated a significant third-order nonlinear Hall effect induced by quantum metric in Fe5GeTe2 at room temperature.
- Confirmed the effect's independence from scattering time and its dependence on electron spin.
- Achieved an ultrahigh third-order conductivity of 72 μm·S·V⁻², tenfold higher than previous Berry curvature-induced effects.
- Showcased enhanced third-order current conversion efficiency.
Conclusions:
- Quantum metrics can drive third-order nonlinear Hall effects at room temperature.
- The findings pave the way for developing advanced room-temperature, low-power quantum spintronic devices.
- This research highlights the potential of quantum geometry in next-generation electronic devices.
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