メンバー

 

ishizuka

Engineering No. 6, Rm 211
7-3-1 Hongo, Bunkyo, Tokyo, 113-8656, JAPAN
E-mail: ishizuka [at] appi.t.u-tokyo.ac.jp

 

gakureki

2009 BEng in Applied Physics, Tohoku University
2011 MEng in Applied Physics, The University of Tokyo
2013 PhD in Applied Physics, The University of Tokyo

 

syokureki

2013 JSPS Postdoctoral Researcher (PD), KITP
2014 JSPS Postdoctoral Researcher for Research Abroad, KITP
2015 Assistant Professor, The University of Tokyo

 

pub

[6] H. Ishizuka, T. Hayata, M. Ueda, N. Nagaosa, “Emergent electromagnetic induction and adiabatic charge pumping in non-centrosymmetric Weyl semimetals”, preprint (arXiv:1607.06537).
[5] Y. Kohama, Z. Tian, T. Tomita, J. J. Ishikawa, K. Kindo, S. Nakatsuji, H. Ishizuka, “Metal-insulator transition sensitive to magnetic field orientation in the Pyrochlore iridates Nd2Ir2O7”, Sol. Stat. Phys. (個体物理) 51, 339 (2016).
[4] R. Takashima, H. Ishizuka, L. Balents, “Quantum Skyrmions in two-dimensional chiral magnets”, to be published in Phys. Rev. B.
[3] J. Iaconis, H. Ishizuka, D.-N. Sheng, L. Balents, “Extended ferromagnetism in an infinite-U bilayer Hubbard model”, Phys. Rev. B 93, 155144 (2016).
[2] T. Hsieh, H. Ishizuka, L. Balents, T. L. Hughes, “Bulk topological proximity effect”, Phys. Rev. Lett. 116, 086802 (2016).
[1] Z. Tian, Y. Kohama, T. Tomita, H. Ishizuka, T. Hsieh, J. J. Ishikawa, K. Kindo, L. Balents, S. Nakatsuji, “Field-induced quantum metal-insulator transition in Pyrochlore iridates Nd2Ir2O7”, Nat. Phys. 12, 134 (2016).

 

oral

◆は招待講演
[4] Hiro Ishizuka, “Emergent electromagnetic induction in Weyl semimetals”, International Workshop on Bulk-Edge Correspondence 2016, Sep. 2016, Kyoto.
[3] Hiro Ishizuka, Tomoya Hayata, Masahito Ueda, Naoto Nagaosa, “Nonlinear response from emergent electromagnetic field in Weyl semimetals”, JPS Fall Meeting 2016, Sep. 2016, Kanazawa.
[2] Hiro Ishizuka, Leon Balents, “Switching of magnetic anisotropy in magnets with strong spin-orbit coupling”, JPS Annual Meeting 2016, Mar. 2016, Sendai.
[1] Hiro Ishizuka, Leon Balents, “Switching of magnetic anisotropy in magnets with strong spin-orbit coupling”, APS March Meeting 2016, Mar. 2016, Baltimore.

 

受賞歴

2015 Springer Thesis Prize
2014 JSPS Fellowship for Research Abroad
2011 JSPS Fellowship for Young Scientists (DC1)

 

theme

I am a condensed matter theorist working in the field of correlated electron systems. Solid state materials are interesting systems where we can engineer novel physics that arise from the interplay of many degrees of freedoms, such as electrons, spins, lattice, etc. My research interest includes broad range of topics in magnetism and quantum transport phenomena. My former research projects involve fluctuation effects in magnetism and transport phenomena, while I have an increasing interest in the topological phenomena in correlated electron and non-equilibrium systems. These are some keywords from my previous projects:

1. Frustrated Magnetism:
Frustration, in magnetism, refers to a situation where two or more interaction competes against each other. The frustration often enhances the fluctuation of spins, and in an extreme case, they may destroy magnetic orders (completely or partially) replacing it by a novel phase. We theoretically studied such possibility in Kondo lattice models on geometrically frustrated lattices, and proposed novel magnetic phases realized in the Kondo lattice models: spin-cluster formation, loop-liquid phase, and partial disorder in low dimensions.

2. Transport phenomena in frustrated Kondo lattices:
The magnetic fluctuations also affect the transport phenomena of electrons that couples to the magnetic moments. We studied the effects of fluctuation induced by geometrical frustration, and shown that the fluctuation may give rise to interesting transport phenomena, such as spin-Hall and quantum anomalous Hall effects.

3. Magnetism in presence of Strong Spin-Orbit Interactions:
Effect of spin-orbit interactions on magnetism have become an increasingly important field. The interaction couples spins to the underlying lattice, and as a consequence, gives rise to novel magnetic interactions such as bond-dependent Ising and Dzyaloshinskii-Moriya interactions. We studied the fluctuation effect on such systems, and found the magnetic interactions give rise to temperature dependent magnetic anisotropy (that flips its sign in some cases!) and lattice instability.

4. Weyl Semimetals:
Weyl semimetals are a special kind of semimetal, which the electron and hole pockets form a nodal cone. The effective Hamiltonian is given by the Weyl Hamiltonian, by which many of its unusual properties are explained. In a recent study, we theoretically proposed a new idea on a photovoltaic effect induced by the Berry phase. The idea is understood as an electromagnetic induction in momentum space, which is a condensed matter realization of adiabatic charge pumping.