Magnetic Field Induced Quantum Metric Dipole in Dirac Semimetal Cd3As2
Abstract
The quantum geometry, comprising Berry curvature and quantum metric, plays a fundamental role in governing electron transport phenomena in solids. Recent studies show that the quantum metric dipole drives scattering-free nonlinear Hall effect in topological antiferromagnets, prompting the questions of whether this effect can occur in nonmagnetic systems and be externally tuned by a magnetic field. Our work addresses these frontiers by demonstrating that the quantum metric dipole is actively tuned by an external magnetic field to generate a time-reversal-odd nonlinear Hall response in a nonmagnetic topological Dirac semimetal Cd3As2. Alongside the well-known chiral-anomaly-induced negative longitudinal magnetoresistance, an exotic nonlinear planar Hall effect emerges with increasing magnetic field. Careful scaling analysis indicates that this nonlinear planar Hall effect is controlled by the magnetic-field-modulated quantum metric dipole. Constructing a k.p effective model of the Dirac bands under Zeeman and orbital coupling, we derive the evolution of the quantum metric dipole as a function of the magnetic field, providing a comprehensive explanation of the experimental results. Our results establish a band-structure-based strategy for engineering nonlinear magnetotransport in nonmagnetic materials via the quantum metric dipole, opening a pathway toward magnetic-field-tunable nonlinear quantum devices.
Cite
@article{arxiv.2508.07364,
title = {Magnetic Field Induced Quantum Metric Dipole in Dirac Semimetal Cd3As2},
author = {Tong-Yang Zhao and An-Qi Wang and Zhen-Tao Zhang and Zheng-Yang Cao and Xing-Yu Liu and Zhi-Min Liao},
journal= {arXiv preprint arXiv:2508.07364},
year = {2025}
}