I am interested in solids, which are composed of many microscopic components, e.g., atoms and molecules. Such materials exhibit dramatic and interesting phenomena, phase transitions and nonlinear responses, due to interactions among their constituents. There remain many not yet understood phenomena that will require highly-sophisticated theoretical treatments beyond one-body approximations. I am trying to explain these exotic phenomena using analytical and computational techniques.
Specifically, I study, from both microscopic and phenomenological viewpoints, dynamical/nonlinear responses of condensed matter, in particular, cooperative phenomena related to optically-excited states of quantum many-body systems to explain their nonlinearity, quantum fluctuation, and spatiotemporal evolution. In other words, I explore coupled systems, where the fermionic (electronic) fields and the bosonic (photonic, phononic, excitonic, biexcitonic) fields are interacting with each other.
One of my main subjects is the "electron-hole (e-h) systems" in photoexcited semiconductors, where the Coulomb interaction leads to the formation of various phases such as the exciton gas, e-h plasma, e-h liquids, exciton Bose-Einstein condensation, and e-h BCS condensate. I perform systematic and quantitative surveys of such phases focusing on the following: (i) Search for the phase diagram of e-h ensembles including the exciton condensation and Mott transition. (ii) Evaluation of dynamical and coherence properties of light emitted from such e-h ensembles. (iii) Theoretical modeling of the dynamics of quantum phase transition of e-h ensembles.
1. Theory of dynamically correlated electron (DYCE) systems
2. Theory of photoinduced electronic phase transitions
3. Theory of photoinduced structural phase transitions
4. Theory of lasing in correlated electron-hole-photon systems
5. Interplay between quantum coherences of light and matter
6. Development of numerically-computational schemes for quantum many-body systems
A. Ishikawa and T. Ogawa, "Carrier dynamics in a quantum wire: Effects of microscopic scattering processes on intraband relaxation and optical properties", J. Phys. Soc. Jpn. 79, 014706 (2010).
T. Ogawa, Y. Tomio, and K. Asano, "Quantum condensation in electron-hole systems: excitonic BEC-BCS crossover and biexciton crystallization", J. Phys.: Cond. Matter 19, 295205 (2007).
Y. Tomio, K. Honda, and T. Ogawa, "Excitonic BCS-BEC crossover at finite temperature: Effects of repulsion and electron-hole mass difference", Phys. Rev. B 73, 235108 (2006).
T. Ogawa, "Quantum states and optical responses of low-dimensional electron-hole systems", J. Phys.: Cond. Matter 16, S3567 (2004).
S. Okumura and T. Ogawa, "Boson representation of two-exciton correlations: An exact treatment of composite-particle effects", Phys. Rev. B 65, 035105 (2002).
April 1981 – March 1985:
Department of Applied Physics, The University of Tokyo, Bachelor course
April 1985 – March 1987:
Department of Applied Physics, The University of Tokyo, Master course
April 1987 – September 1988:
Department of Applied Physics, The University of Tokyo, Ph. D. course
Ph.D., The University of Tokyo
October 1988 – March 1990:
Assistant Professor, Department of Applied Physics, The University of Tokyo
April 1990 – September 1993:
Researcher, Basic Research Laboratories, NTT Corporation
October 1993 – July 1996:
Associate Professor, Department of Applied Physics, Osaka City University
August 1996 – April 2000:
Associate Professor, Department of Physics, Tohoku University
October 1997 – September 2000:Concurrent researcher, PRESTO (Precursory Research for Embryonic Science and Technology), Japan Science and Technology Agency (JST)
May 2000 – March 2001:
Concurrent Professor, Department of Physics, Tohoku University
May 2000 – present:
Professor, Department of Physics, Osaka University
April 2007 – March 2009:
Chair, Department of Physics, Osaka University
December 2008 – present:
Guest Professor, Shanghai Jiao Tong University
January 2009 – present:
Vice-director, Photon Pioneers Center, Osaka University