QUANTUM MATERIALS AND DEVICES SEMINARS: Nonlinear response in strongly correlated systems

DIPC Seminars

Speaker

Robert Peters, Department of Physics, Kyoto University, Kyoto (Japan)

When

2021/12/08
11:00

Place

Online Seminar, Donostia International Physics Center

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** NOTE THE CHANGE OF STARTING TIME DUE TO THE DIFFERENCE IN TIME BETWEEN JAPAN AND CENTRAL EUROPE ** Nonlinear responses in condensed matter are intensively studied because they provide rich information about materials and hold the possibility of being applied in diodes or high-frequency optical devices [1-4]. While nonlinear responses in noninteracting models have been explored widely, the effect of strong correlations on the nonlinear response is still poorly understood. This talk will introduce a Green's function method to calculate nonlinear conductivities in strongly correlated materials [5-6]. Correlation effects are thereby included by the self-energy of the material. I will then use this method to study the nonlinear conductivities in noncentrosymmetric f-electron systems. The first system is a heavy Fermion system, where a nonreciprocal conductivity appears in the ferromagnetic phase. The nonreciprocal conductivity thereby always occurs perpendicular to the magnetization of the system and has a strong spin dependence, which might be advantageous for spintronic applications. The second system is a model corresponding to the Weyl-Kondo semimetal Ce3Bi4Pd3, in which a giant spontaneous Hall effect without time-reversal symmetry breaking has been observed [7]. This Hall effect can be explained as a nonlinear Hall effect in an inversion-symmetry broken Weyl-semimetal. It has been shown that the nonlinear Hall effect is related to the Berry curvature dipole [4]. Our study shows that the magnitude of the experimentally observed nonlinear Hall effect can be explained by the strong correlations inherent in this f-electron material [8]. References: 1\. Y Tokura and N Nagaosa, Nature Comm. 9, 3740 2\. T Morimoto and N Nagaosa, Science Advances 2, DOI: 10.1126/sciadv.1501524 3\. Q. Ma et al., Nature 565, 337–342 4\. I Sodemann and L Fu, Rev. Lett. 115, 216806 5\. Daniel E. Parker, Rev. B 99, 045121 6\. Y Michishita and R Peters, Rev. B 103, 195133 7\. S Dzsaber et al., PNAS 118 e2013386118 8\. A Kofuji, Y Michishita, and R. Peters, Rev. B 104, 085151 9\. K Shinada and R Peters, arXiv:2110.10496 Host: Miguel A. ZOOM: https://dipc- org.zoom.us/meeting/register/tZAqceGqrzMqE9fPWdhzaKxoIscCspVlFJ4Y