Intrinsic nonlinear conductivity induced by quantum geometry in altermagnets and measurement of the in-plane N\'{e}el vector
| Autor: | Ezawa, Motohiko |
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| Rok vydání: | 2024 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | The $z$-component of the N\'{e}el 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 N\'{e}el 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 N\'{e}el vector, and hence, the in-plane component of the N\'{e}el 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. Comment: 6 pages, 3 figures |
| Databáze: | arXiv |
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