Intrinsic nonlinear conductivity induced by quantum geometry in altermagnets and measurement of the in-plane Néel vector

Abstract

The $z$-component of the Néel vector is measurable by the anomalous Hall conductivity in altermagnets because time reversal symmetry is broken. On the other hand, it is a nontrivial problem how to measure the in-plane component of the Néel vector. We study the second-order nonlinear conductivity of a system made of the $d$-wave altermagnet with the Rashba interaction. It is shown that the quantum-metric induced nonlinear conductivity and the nonlinear Drude conductivity are proportional to the in-plane component of the Néel vector, and hence, the in-plane component of the Néel vector is measurable. We obtain analytic formulas of the quantum-metric induced nonlinear conductivity and the nonlinear Drude conductivity both for the longitudinal and transverse conductivities. The quantum-metric induced nonlinear conductivity diverges at the Dirac point, while the nonlinear Drude conductivity is always finite. Hence, the quantum-metric induced nonlinear conductivity is dominant at the Dirac point irrespective of the relaxation time.

6 pages, 3 figures

References in corpus (6)

• Antiferromagnetism in RuO${}_2$ as $d$-wave Pomeranchuk instability
• Quantum metric nonlinear Hall effect in a topological antiferromagnetic heterostructure
• Perovskite as a spin current generator
• Abelian and Non-Abelian Quantum Geometric Tensor
• Interplay between altermagnetism and nonsymmorphic symmetries generating large anomalous Hall conductivity by semi-Dirac points induced anticrossings
• Suppressed Kondo screening in two-dimensional altermagnets

Cited by in corpus (8)

• Bulk photovoltaic effects in altermagnets
• Quantum geometry and $X$-wave magnets with $X=p,d,f,g,i$
• Nonlinear Hall effects with an exceptional ring
• Almost half-quantized planar Hall effects in $X$-wave magnets with $X=p,d,f,g,i$
• Two-Terminal Electrical Detection of the Néel Vector via Longitudinal Antiferromagnetic Nonreciprocal Transport
• Tunneling magnetoresistance in a junction made of $X$-wave magnets with $X=p,d,f,g,i$
• Nonlinear spin-Seebeck diode in $f$-wave magnets, third-order spin-Nernst effects in $g$-wave magnets and spin-Nernst effects in $i$-wave altermagnets
• Electric field controlled second-order anomalous Hall effect in altermagnets