セミナー案内

日時
12月2日 (水), 13:30-
場所
Zoom Online Seminar
(URLはwatanabe.hikaru.43n[アット]st.kyoto-u.ac.jpまでお問い合わせください。)
講演者
Hiroomi Chono
(Condensed matter theory group)
タイトル
"Nonequilibrium quantum phenomena and topological superconductivity in atomic layer materials"
備考欄 (アブストラクト等)

Abstract:
Thanks to the recent breakthrough in THz wave and intensive short-pulse laser techniques, novel physical phenomena that are difficult to be stabilized in an equilibrium state have been vigorously studied both theoretically and experimentally. These studies play a key role in controlling topological phases in solid-states of matter. As pioneering studies, quantum anomalous Hall state was theoretically proposed in graphene [1], and the observation of this phenomenon was reported last year [2]. The optical control techniques are also useful for designing topological superconductivity (TSC). For example, topological d-wave superconductivity induced with laser light was theoretically proposed in cuprate thin films [3].
On the other hand, the recent progress of nanotechnology and atomic layer materials research has created an experimental environment for two-dimensional superconductivity with atomically thin materials. As one of the methods to do, the electric double-layer transistor (EDLT) technique enables us to realize clean superconductivity phases in the atomic layer materials such as transition metal dichalcogenides (TMD) [4] and ZrNCl.
In our work, we proposed a way to realize topological s-wave superconductivity with the application of circularly polarized laser light in the transition metal dichalcogenides bilayer [5].
Reference:
[1] T. Oka and H. Aoki, Phys. Rev. B 79, 081406 (2009).
[2] J. W. McIver, B. Schulte, F.-U. Stein, T. Matsuyama, G. Jotzu, G. Meier, and A. Cavalleri, Nat. Phys. 16, 38 (2020).
[3] K. Takasan, A. Daido, N. Kawakami, and Y. Yanase, Phys. Rev. B 95, 134508 (2017).
[4] J. Ye, Y. Zhang, R. Akashi, M. Bahramy, R. Arita, and Y. Iwasa, Science 338, 1193 (2012).
[5] HC, K. Takasan, and Y. Yanase, Phys. Rev. B 102, 174508 (2020).