Nonlinear Hall Effect in Altermagnetic Warped Topological Insulators

Abstract:Low-dimensional Dirac systems offer a versatile platform for quantum-geometric non-linear transport. Hexagonal warping in topological insulator (TI) surface states generates rich momentum-space geometric textures. However, mirror and time-reversal symmetries strictly constrain both the Berry curvature and quantum metric dipoles to zero. Here, we show that proximity-coupling a hexagonally warped TI to a d-wave altermagnet lifts spatial mirror symmetry via the interplay of C_{3v} warping and d-wave spin-splitting. This symmetry breaking enables finite Berry curvature dipole components, which, however, remain heavily suppressed near charge neutrality, establishing the intrinsic quantum metric dipole as the sole driver of the non-linear Hall response. This scattering-independent response vanishes at \mu = 0 and exhibits odd parity under chemical potential inversion. Importantly, rotating the altermagnetic orientation angle \phi continuously tunes quantum metric dipole and induces a sign reversal, peaking near \phi=0 and vanishing at \phi = \pi/4. Our findings highlight TI-altermagnet interfaces as ideal candidates for gate- and orientation-tunable quantum metric spintronics.

Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Quantum Physics (quant-ph)

arXiv:2609.17001 [cond-mat.mes-hall]

(or arXiv:2609.17001v1 [cond-mat.mes-hall] for this version)

https://doi.org/10.48550/arXiv.2609.17001 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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