Electrons have two properties, charge and spin. While the technology that controls the degree of freedom of charge is conventional electronics, "Spintronics" is a new technology that controls both "charge" and "spin", which are the basic properties of electrons. Hence, spintronics could bring innovation to electronics, which is a control technology by charge degrees of freedoms. Recently, a study of electronics and optics in topological materials (e.g., Dirac semimetal [1], Weyl semimetal [2], and line-node semimetals [3]), which host Dirac and Weyl fermions in bulk, have been attracting much attention. The properties of Dirac and Weyl fermions have been both theoretically and experimentally studied in many fields of physics. These fermions drive unconventional transport and optical responses [4]. These phenomena could be applicable to novel electrical and optical functional devices in future.

Among these characteristic phenomena in topological materials, in this talk, we will present a study of light-induced charge current (dubbed as photovoltaic chiral magnetic effect) in Weyl semimetal [5]. Here, the photovoltaic chiral magnetic effect is caused when we apply circularly polarized light in Weyl semimetals with time-reversal symmetry. The applied circularly polarized light generates the charge current along the light propagation direction. Its charge flow is controllable by chirality of the circularly polarized light via inverse Faraday effect [6].

Besides, we will talk the study of photovoltaic anomalous Hall effect in line-node semimetals (e.g., Ca₃P₂). The photovoltaic effect is the optical anisotropic, and it could be applicable to photodetector based on the line-node semimetals [7].

[1] M. N. Ali, et al., Chem. 53, 4062 (2014), Z. Liu, et al., Nat. Mater. 13, 677 (2014).

[2] S.Huang et al., Nat. Comm. 6, 7373 (2014), H.Weng et al., Phys. Rev. X 5, 011029 (2015)

[3] L.S. Xie et al., APL Mater. 3, 083602 (2015).

[4] A. A. Burkov, Nat. Mater. 15, 1145 (2016).

[5] K. Taguchi, T. Imaeda, M. Sato, and Y. Tanaka, Phys. Rev. B 93, 201202(R) (2016).

[6] A. Kirilyuk, A. V. Kimel, and T. Rasing, Rev. Mod. Phys. 82, 2731 (2010).

[7] K. Taguchi, D.-H. Xu, A. Yamakage, and K. T. Law, Phys. Rev. B 94, 155206 (2016).

CONDENSED MATTER THEORY 

I did my graduate work at Tokyo Metropolitan University, and I received the PhDdegree in 2013. After spending 5 year as a postdoc of Research Fellowship for YoungScientist in Nagoya University, I joined the Kyoto University (YITP) in 2018. Myresearch is supported by JSPS foundation.  

RESEARCH INTEREST 

I am interested in condensed matter theory. My research focus is on spintronics intopological insulators, Weyl semimetal, and other topological materials. Most ofmy recent works are related to the unconventional spin-related transport inWeyl/Diracsemimetal as well as spin-related optical responses in topological insulators and transition metal dichalcogenides.