Topological Quantum Phenomena in Condensed Matter with Broken Symmetries

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Member Profile

Yoshiteru Maeno

Ryuji NOMURA

Assistant Professor, Department of Physics, Tokyo Institute of Technology
Field of Specialty:
Low temperature physics
Topics of Research:
(B01) Novel Edge Phenomena in Spin-Triplet Superfluids
Specific Topics:
Magnetic field effect on surface bound states in superfluid 3He
■ Laboratory Website

RESEARCH

I have investigated the response of topologically protected Andreev bound states appearing at a surface of superfluid 3He to transverse acoustic wave. In p-wave superfluids, surfaces and impurities act as strong pair brakers. As a result, unusual quasiparticle states are expected around such surfaces and impurities. In particular at a surface of superfluid 3He, it is turned out that the bound state is described by unusual excitation so called Majorana fermion excitation as well as it is in the noncentrosymmetric superconductors (studied in Group C01) and in the chiral superconductor (studied in Group A01). To study features of the Majorana fermion modes in 3He, we have measured the acoustic impedance. The transverse acoustic impedance is a unique surface probe which tells us spectroscopic details of the surface density of states.

In this project, I will investigate effects of external magnetic field on the Majorana surface bound states in superfluid 3He-B phase. In addition, I try to find new phases which are stabilized in the presence of magnetic field.

EDUCATION

1991
Bachelor of Science, Kyoto University
2000
Ph.D. (Physics), Kyoto University

PROFESSIONAL EXPERIENCE

1998-2000
Research fellow, Northwestern University
2000-2007
Research associate, Graduate School of Science, Tokyo Institute of Technology
2007-Present
Assistant Professor, Department of Physics, Tokyo Institute of Technology

HONORS AND AWARDS

2007
Young Scientist Award of Physical Society of Japan

SELECTION OF PUBLICATIONS

"Ripening of Splashed 4He Crystals by Acoustic Waves with and without Gravity",
T. Takahashi, H. Ohuchi, R. Nomura, and Y. Okuda
New J. Phys. 14, 123023-1-11 (2012).

"Surface Andreev bound states of superfluid 3He and Majorana Fermions",
Y. Okuda and R. Nomura
J. Phys.: Cond. Matt. 24, 343201-1-19 (2012). Topical Review

"Strong suppression of the Kosterlitz-Thouless transition in a 4He film under high pressure",
S. Murakawa, M. Wasai, K. Akiyama, Y. Wada, Y. Tamura, R. Nomura and Y. Okuda
Phys. Rev. Lett. 108, 025302 (2012).

"Surface Majorana Cone of the Superfluid 3He B Phase",
S. Murakawa, Y. Wada, Y. Tamura, M. Wasai, M. Saitoh, Y. Aoki, R. Nomura, Y. Okuda, Y. Nagato, M. Yamamoto, S. Higashitani, and K. Nagai
J. Phys. Soc. Jpn. 80, 013602-1-4 (2011).

"New anomaly in the transverse acoustic impedance of superfluid 3He-B with a wall coated by several layers of 4He",
S. Murakawa, Y. Tamura, Y. Wada, M. Wasai, M. Saitoh, Y. Aoki, R. Nomura, Y. Okuda, Y. Nagato,M. Yamamoto, S. Higashitani, and K. Nagai,
Phys. Rev. Lett. 103, 155301(1)-(4) (2009).

"Broadening of the surface Andreev bound states band of superfluid 3He-B on a partially specular wall",
Y. Wada, S. Murakawa, Y. Tamura, M. Saitoh, Y. Aoki, R. Nomura, and Y. Okuda,
Phys. Rev. B 78, 214516(1)-(5) (2008).

"Competition between thermal fluctuations and disorder in the crystallization of 4He in aerogel",
R. Nomura, A. Osawa, T. Mimori, K. Ueno, H. Kato, and Y. Okuda,
Phys. Rev. Lett. 101, 175703(1)-(4) (2008).

"Observation of Surface Andreev Bound States of Superfluid 3He by Transverse Acoustic Impedance Measurements",
Y. Aoki, Y. Wada, M. Saitoh, R. Nomura, Y. Okuda, Y. Nagato, M. Yamamoto, S. Higashitani, and K. Nagai,
Phys. Rev. Lett. 95, 075301(1)-(4) (2005).

"Interface Motion and Nucleation of Solid Helium-4 Induced by Acoustic Waves",
R. Nomura, Y. Suzuki, S. Kimura, and Y. Okuda,
Phys. Rev. Lett. 90, 075301(1)-(4) (2003).

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