Outline of Project D02

Tensor Networks and Quantum Many-Body Systems from Quantum Information (21H05191)

Principal Investigator: Kouichi Okunishi

Quantum many-body systems such as quantum spin systems, ultra-cold atoms, and topological quantum matter, have been a central issue in modern condensed matter physics. The key to understanding such complex systems is the structure of quantum entanglement. The primary goal of group D02 is to precisely understand the physics of quantum many-body systems based on a quantitative analysis of quantum entanglement. For this purpose, we focus on tensor networks (TNs) that provide very practical numerical and theoretical frameworks for describing and controlling entangled many-body states. Recent years have witnessed a growing interest in applying TNs to various fields, ranging from quantum information to high-energy physics. In particular, the fusion of different fields has led to nontrivial results such as the relation between the Ryu-Takayanagi formula and the entanglement renormalization group, one of the TN methods. In this research project, motivated by such interesting interdisciplinary developments, we will systematically clarify the controlling mechanism of quantum many-body states using TNs, and then develop a modern theory of quantum many-body dynamics by focusing on mathematical structures behind the TNs and quantum entanglement. Also, we will address TN algorithms for higher dimensions and critical systems. In cooperation with other research groups, moreover, we explore condensed matter analogies of quantum gravity phenomena in realistic experimental situations, which would provide a possible understanding of quantum universe from the condensed matter perspective.

Members in D02

[Principal Investigator]
Kouichi Okunishi Department of Physics, Niigata University

[Co-Investigator]
Kenji Harada Graduate School of Informatics, Kyoto University
Chisa Hotta Graduate School of Arts and Sciences, The University of Tokyo
Hosho Katsura Graduate School of Science, The University of Tokyo
Hiroshi Ueda Center for Quantum Information and Quantum Biology, Osaka University

[ExU Postdoctoral Fellows(Research Collaborators)]
Shunsuke Furuya, Graduate School of Arts and Sciences, The University of Tokyo
Atis Yosprakob Department of Physics, Niigata University

[Research Collaborators]
Toshiya Hikihara, Faculty of Science and Technology, Gunma University
Tomotoshi Nishino, Department of Physics, Kobe University
Tsuyoshi Okubo, Graduate School of Science, The University of Tokyo

[Graduate Students]
Atsushi Iwaki, Graduate School of Arts and Sciences, The University of Tokyo
Koutaro Nakajima, Graduate School of Natural Science, Niigata University