We are interested in nonequilibrium physics of quantum many-body systems and statistical mechanics. The aim is to realize a new order or new physical property by driving quantum systems out of equilibrium. At first sight, it sounds unlikely to happen because energy injected by an external drive would turn into heat, which would destroy all the interesting properties of quantum many-body systems that might emerge at low energies. However, contrary to our intuition, recent studies have found various possibilities such that novel states of matter that can never be realized in equilibrium do emerge out of equilibrium. We are trying to understand their mechanism and explore the frontier of nonequilibrium condensed matter physics.
News
・08/08/2025 Taiga Nakamoto and Shuta Matsuura have received a Best Poster Award in ISSP-IIS Joint Symposium on Physics of Open Systems: Resonance, Symmetry and Topology (POS-RST 2025).
・06/08/2025 We had a seminar “Spectroscopy of collective modes in multi-components superconductors” given by Silvia Neri (Max Planck Institute for Solid State Research).
・02/08/2025 Shuta Matsuura has been elected as an outstanding presenter at the 70th Condensed Matter Physics Summer School.
・15/07/2025 We had a StatPhys seminar, “Practical quantum algorithms for many-body simulation”, given by Prof. Nobuyuki Yoshioka (ICEPP, University of Tokyo).
・07/07/2025 We published a paper, “Optically active Higgs and Leggett modes in multiband pair-density-wave superconductors with Lifshitz invariant” (R. Nagashima, T. Mouilleron, N. Tsuji, Phys. Rev. B 112, 024503 (2025)).
・02-04/07/2025 We organized “Mini-symposium on magnetic semiconductors and nonequilibrium dynamics 2025” for KAKENHI Kiban A project “Real and reciprocal spacetime imaging of many-body excitons and quantum phase control” at Okinawa Institute of Science and Technology (OIST).
・16/05/2025 Our group has an open position for a postdoc researcher. For details, see here.
・08/05/2025 We held the kick-off meeting for Grant-in-Aid for Transformative Research Areas (A) “Correlation Design Science”.
・28/04/2025 We published a paper, “Tensor cross interpolation approach for quantum impurity problems based on the weak-coupling expansion” (S. Matsuura, H. Shinaoka, P. Werner, N. Tsuji, Phys. Rev. B 111, 155150 (2025)).
・28/04/2025 We published a paper, “Light-driven interlayer propagation of collective mode excitations in layered superconductors” (N. Ziereis, K. Takasan, N. Tsuji, Phys. Rev. B 111, 134520 (2025)).
・25/04/2025 Tsuji gave an invited talk at “Conference on Laser and Synchrotron Radiation Combination Experiment (LSC2025)” (Yokohama).
・03/04/2025 Chihiro Mamiya and Keito Yamamoto joined our group as Master students.
・01/04/2025 Grant-in-Aid for Transformative Research Areas (A) “Correlation Design Science” (Project leader: Ryotaro Arita) has been accepted, and a new research project has started.
・24/03/2025 Raigo Nagashima and Taiga Nakamoto got the Master degrees.
・27/01/2025 We published a lecture note of Condensed Matter Physics Summer School, “Physics of nonequilibrium superconductivity”, from J-STAGE.
・16/01/2025 We published a paper, “Quantum many-body scars with unconventional superconducting pairing symmetries via multibody interactions” (S. Imai, N. Tsuji, Phys. Rev. Research 7, 013064 (2025)).
・26/12/2024 We published a paper, “Boundary dissipative spin chains with partial solvability inherited from system Hamiltonians” (C. Matsui, N. Tsuji, Phys. Rev. B 110, 224306 (2024)).
・23/12/2024 Tsuji gave a talk, “Numerical analysis for nonequilibrium quantum many-body systems”, at Sohatsu Kenkyu Koryukai (Department of Physics, University of Tokyo).
・18/11/2024 We had a StatPhys seminar given by Dr. Ken Mochizuki (University of Tokyo) with the title “Measurement-induced spectral transition and entanglement transition”.
・11-12/11/2024 We organized a workshop “Frontiers of Nonequilibrium Solid States 2024” at Kyoto University.
・10/10/2024 Tsuji gave a talk, “Collective modes in superconductors: Modern perspective”, at Condensed Matter Colloquium at Nagoya University (co-organized by Toyota Physical and Chemical Research Institute).
・02/10/2024 Gerrit Niederhoff joined our group as a visiting research student.
・16-19/09/2024 We joined the annual JPS meeting at Hokkaido University.
・03-05/08/2024 Tsuji gave an intensive lecture at Condensed Matter Physics Summer School (2024). The lecture note (long ver.) and the Julia sample code have been uploaded.
・27/06/2024 A Youtube video explaining our recent work on multiband superconductors has been released.
・24-25/06/2024 We organized a workshop 2024 for KAKENHI Kiban A project “Real and reciprocal spacetime imaging of many-body excitons and quantum phase control” at Okinawa Institute of Science and Technology (OIST).
・20/06/2024 Tsuji gave a seminar talk, “Higgs and Leggett modes and Lifshitz invariant in superconductors”, at ETH Zurich.
・19/06/2024 Takasan’s research has been featured in Gendai Kagaku (July, 2024).
・17/06/2024 Tsuji gave an invited talk at the international conference “Trends in the Theory of Quantum Materials” (University of Fribourg).
・30/05/2024 We had a StatPhys seminar given by Dr. Pasquale Marra (University of Tokyo) with the title “Majorana modes, topologically nontrivial stripes, and inhomogeneous superconductivity in 2D topological insulator/superconductor heterostructure”.
・15/05/2024 The lecture note (short ver.) for Condensed Matter Physics Summer School (2024) has been uploaded.
・04/04/2024 Shuta Matsuura joined our group as a Master student.
・01/04/2024 KAKENHI Grant-in-Aid for Scientific Research (A) “Real and reciprocal spacetime imaging of many-body excitons and quantum phase control” (Project leader: Tsuji) has been accepted, and a new research project has started.
・27/03/2024 Tsuji gave a seminar talk, “Quantum many-body scars with unconventional pairings”, at College de France (Paris, France).
・26/03/2024 Tsuji gave an invited talk at ENS Paris-UTokyo workshop at The Henri Poincare Institute (Paris, France).
・21/03/2024 Hiromu Ushihara and Shunsuke Nishimura got the Master degrees.
・18/03/2024 We published a paper, “Exact steady states of the impurity-doped XXZ spin chain coupled to dissipators” (C. Matsui, N. Tsuji, J. Stat. Mech. 033105 (2024)).
・06/03/2024 Titouan Mouilleron joined our group as a visiting research student.
・30/01/2024 We published a paper, “Classification of Lifshitz invariant in multiband superconductors: An application to Leggett modes in the linear response regime in Kagome lattice models” (R. Nagashima, S. Tian, R. Haenel, N. Tsuji, D. Manske, Phys. Rev. Research 6, 013120 (2024)). We also published a press release.
Past news can be found here.
Research introduction video
Tsuji and Nagashima explained our recent work on multiband superconductors (in Japanese) featured in Press release.
Kazuaki Takasan gave an introductory talk (in Japanese) in Online lecture for high school students.
Contact
Naoto Tsuji
Department of Physics, University of Tokyo
Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
E-mail: tsuji [at] phys.s.u-tokyo.ac.jp