Muneto NITTA

Associate Professor, Department of Physics at Hiyoshi, Research and Education Center for Natural Sciences, Keio University

Topics of Research：

Study of Topological Excitations based on the Methods in High Energy Physics

■ Description of Research [1051KB]

RESEARCH

I have been studying various topological excitations or defects in quantum field theories, especially supersymmetric gauge theories. Recently I have started to work on topological excitations in cold atomic gasses such as spinor Bose-Einstein condensates (BEC) or two components BECs. At the same time, I am studying vortices in color superconductors of quantum chromo dynamics at high baryon density. I am trying to construct a physics of vortices and solitons as a subject which interpolate condensed matter physics, high energy physics and hadron physics.

In this project "Topological Quantum Phenomena in Condensed Matter with Broken Symmetries", I will pursue several aspects of topological quantum phenomena. There exist non-Abelian vortices in the cyclic phase of spin 2 BECs. First I will study dynamics of these vortices and will investigate a possibility of non-Abelian quantum turbulence. In the nematic phase of spin 2 BEC, there appear a new type of modes called quasi-Nambu-Goldstone (QNG) modes, which have been known in high energy physics but not in condensed matter physics. Classification and stability of topological excitations are drastically changed in the presence of QNG modes. I will construct a physics of QNG modes. I will also study D-branes in two component BECs, and will propose how to construct them in a laboratory. I will study a classification of topological excitations based on the Abe homotopy group. A technique to construct self-consistent solutions of the Bogoliubov-de-Gennes equation in one dimension has been developed. I will generalize this method to chiral p-wave superconductors or two dimensional systems. I will also pursue a possibility to realize supersymmetry in cold atomic gasses.

When multiple zero energy Majorana fermions are trapped in the core of vortices, a new type of non-Abelian exchange statistics is obtained, which is a tensor product of usual non-Abelian statistics and a Coxeter group. Theoretically such vortices are known to exist in color superconductors. I will pursue to realize this new non-Abelian statistics in actual condensed matter systems, and will investigate a new possibility of topological quantum computations.

EDUCATION

1995

B.Sc. in Physics, Osaka University, Department of Physics

1997

M.S. in Physics, Osaka University, Department of Physics

2000

Ph.D. in Physics, Osaka University, Department of Physics

PROFESSIONAL EXPERIENCE

2000-2001

JSPS Postdoc Research Associate, Tokyo Institute of Technology

2001-2003

Postdoc Research Associate, Purdue University

2004-2006

JSPS Postdoc Research Associate, Tokyo Institute of Technology

2006-2009

Senior Assistant Professor Keio University

2009-Present

Associate Professor Keio University

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