My research

keyword

More is different.

P. W. Anderson

OPEN SOFTWARE

Toolkit of Bayesian Scaling Analysis

Reference application software of a new scaling analysis method of critical phenomena based on Bayesian inference.

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Toolkit of Adaptive Tensor Tree Generative Modeling

Reference application software of adaptive tensor tree generative modeling.

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RESEARCH ACTIVITY

Preprints arXiv.org

  1. Kenji Harada, Tsuyoshi Okubo, and Naoki Kawashima: Tensor tree learns hidden relational structures in data to construct generative models, arXiv:2408.10669.
  2. Toshiya Hikihara, Hiroshi Ueda, Kouichi Okunishi, Kenji Harada, Tomotoshi Nishino: Visualization of Entanglement Geometry by Structural Optimization of Tree Tensor Network, arXiv:2401.16000.
  3. Kenji Harada: Universal spectrum structure at nonequilibrium critical points in the (1+1)-dimensional directed percolation, arXiv:2008.10807.

Papers

You can download all preprints from this link. Also, all PDF files of my papers can be downloaded from Kyoto University Research Information Repository (KURENAI) as this link.

  1. Ryosuke Yoneda and Kenji Harada: Neural Network Approach to Scaling Analysis of Critical Phenomena, Physical Review E 107,(2023) 044128. 10.1103/PhysRevE.107.044128.
  2. Chisa Hotta, Tempei Yoshida, and Kenji Harada: Quantum critical dynamics in the two-dimensional transverse Ising model, Physical Review Research 5, (2023) 013186. 10.1103/PhysRevResearch.5.013186.
  3. Toshiya Hikihara, Hiroshi Ueda, Kouichi Okunishi, Kenji Harada, and Tomotoshi Nishino: Automatic structural optimization of tree tensor networks, Physical Review Research 5, (2023) 013031. 10.1103/PhysRevResearch.5.013031.
  4. Ryosuke Yoneda, Kenji Harada, Yoshiyuki Y. Yamaguchi: Critical exponents in coupled phase-oscillator models on small-world networks, Physical Review E 102, (2020) 062212.
    DOI: 10.1103/PhysRevE.102.062212
  5. Hiroshi Ueda, Kouichi Okunishi, Kenji Harada, Roman Krčmár, Andrej Gendiar, Seiji Yunoki, Tomotoshi Nishino: Finite-m scaling analysis of Berezinskii-Kosterlitz-Thouless phase transitions and entanglement spectrum for the six-state clock model, Physical Review E 101, (2020) 062111.
    DOI: 10.1103/PhysRevE.101.062111
  6. Kenji Harada and Naoki Kawashima: Entropy Governed by the Absorbing State of Directed Percolation, Physical Review Letters 123 (2019) 090601.
    DOI: 10.1103/PhysRevLett.123.090601
  7. Kenji Harada: Entanglement branching operator, Physical Review B 97 (2018) 045124.
    DOI: 10.1103/PhysRevB.97.045124
  8. Tsuyoshi Okubo, Kenji Harada, Jie Lou, Naoki Kawashima: SU(N) Heisenberg model with multicolumn representations, Physical Review B 92 (2015) 134404.
    DOI: 10.1103/PhysRevB.92.134404
  9. Kenji Harada: Kernel method for corrections to scaling, Physical Review E 92 (2015) 012106.
    DOI: 10.1103/PhysRevE.92.012106
  10. Takafumi Suzuki, Kenji Harada, Haruhiko Matsuo, Synge Todo, and Naoki Kawashima: Thermal phase transition of generalized Heisenberg models for SU(N) spins on square and honeycomb lattices, Physical Review B 91 (2015) 094414.
    DOI: 10.1103/PhysRevB.91.094414
  11. Kouichi Okunishi and Kenji Harada: Symmetry-protected topological order and negative-sign problem for SO(N) bilinear-biquadratic chains, Physical Review B 89 (2014) 134422.
    DOI: 10.1103/PhysRevB.89.134422
  12. Akiko Masaki, Takafumi Suzuki, Kenji Harada, Synge Todo, and Naoki Kawashima: Parallelized Quantum Monte Carlo Algorithm with Non-local Worm Updates, Physical Review Letters 112 (2014) 140603.
    DOI: 10.1103/PhysRevLett.112.140603
  13. Kenji Harada, Takafumi Suzuki, Tsuyoshi Okubo, Haruhiko Matsuo, Jie Lou, Hiroshi Watanabe, Synge Todo, and Naoki Kawashima: Possibility of Deconfined Criticality in SU(N) Heisenberg Models at Small N, Physical Review B 88 (2013) 220408(R).
    DOI: 10.1103/PhysRevB.88.220408
  14. Jie Lou, Takafumi Suzuki, Kenji Harada and Naoki Kawashima: Study of the Shastry Sutherland Model Using Multi-scale Entanglement Renormalization Ansatz, arXiv:1212.1999.
  15. Kenji Harada: Numerical study of incommensurability of the spiral state on spin-1/2 spatially anisotropic triangular antiferromagnets using entanglement renormalization, Physical Review B 86 (2012) 184421.
    DOI: 10.1103/PhysRevB.86.184421
  16. Kenji Harada: Bayesian inference in the scaling analysis of critical phenomena, Physical Review E 84 (2011) 056704.
    DOI: 10.1103/PhysRevE.84.056704
  17. Kenji Harada and Yuto Kuge: Diffusion in the Continuous-Imaginary-Time Quantum World-Line Monte Carlo Simulations with Extended Ensembles, Journal of the Physical Society of Japan 77 (2008) 013001-1 - 013001-4.
    DOI: 10.1143/JPSJ.77.013001
  18. Kenji Harada, Naoki Kawashima and Matthias Troyer: Dimer-Quadrupolar Quantum Phase Transition in the Quasi-One-Dimensional Heisenberg Model with Biquadratic Interaction, Journal of the Physical Society of Japan 76 (2007) 013703-1 - 013703-4.
    DOI: 10.1143/JPSJ.76.013703
  19. (INVITED REVIEW PAPER) Naoki Kawashima and Kenji Harada:
    Recent Developments of World-Line Monte Carlo Methods,
    Journal of the Physical Society of Japan 73 (2004) 1379 - 1414.
    DOI: 10.1143/JPSJ.73.1379 (FREE)
  20. Jurij Smakov, Kenji Harada and Naoki Kawashima: Quantum Monte Carlo algorithm for softcore boson systems, Physical Review E 68 (2003) 046708.
    DOI: 10.1103/PhysRevE.68.046708
  21. Kenji Harada, Naoki Kawashima and Matthias Troyer: Neel and Spin-Peierls Ground States of Two-Dimensional SU(N) Quantum Antiferromagnets, Physical Review Letters 90 (2003) 117203.
    DOI: 10.1103/PhysRevLett.90.117203
  22. Kenji Harada and Naoki Kawashima: Coarse-grained loop algorithms for Monte Carlo simulation of quantum spin systems, Physical Review E 66 (2002) 056705; ibid. 67 (2003) 039903(E).
    DOI: 10.1103/PhysRevE.66.056705
  23. Kenji Harada and Naoki Kawashima: Quadrupolar order in isotropic Heisenberg models with biquadratic interaction, Physical Review B 65 (2002) 052403.
    DOI: 10.1103/PhysRevB.65.052403
  24. C. Yasuda, S. Todo, K. Harada, N. Kawashima, S. Miyashita and H. Takayama: Classical correlation-length exponent in the nonuniversal quantum phase transition of a diluted Heisenberg antiferromagnet, Physical Review B 63 (2001) 140415(R).
    DOI: 10.1103/PhysRevB.63.140415
  25. Kenji Harada and Naoki Kawashima: Loop Algorithm for Heisenberg Models with Biquadratic Interaction and Phase Transitions in Two Dimensions, Journal of Physical Society of Japan 70 (2001) 13-16.
    DOI: 10.1143/JPSJ.70.13
  26. He-Ping Ying and Kenji Harada: Short-time dynamics and magnetic critical behavior of the two-dimensional rand-bond Potts model, Physical Review E 62 (2000) 174-178.
    DOI: 10.1103/PhysRevE.62.174
  27. S. Todo, C. Yasuda, K. Kato, K. Harada, N. Kawashima, S. Miyashita, H. Takayama: Quantum phase transition of two-dimensional diluted Heisenberg antiferromagnet, Progress of Theoretical Physics Supplement 138 (2000) 507-512.
    DOI: 10.1143/PTPS.138.507
  28. K. Kato, S. Todo, K. Harada, N. Kawashima, S. Miyashita and H. Takayama: Quantum phase transition of the randomly diluted Heisenberg antiferromagnet on a square lattice, Physical Review Letters 84 (2000) 4204-4207.
    DOI: 10.1103/PhysRevLett.84.4204
  29. S. Todo, K. Kato, H. Takayama, K. Harada, N. Kawashima, S. Miyashita: Quantum Monte Carlo study of site-diluted Heisenberg antiferromagnet on a square lattice, International Journal of Modern Physics C 10 (1999) 1399-1407.
    DOI: 10.1142/S0129183199001170
  30. Kenji Harada: Numerical Study of Quantum Spin Models by Loop Algorithm, Doctoral Thesis, Kyoto University (1998).
    DOI: 2433/77874
  31. Kenji Harada and Naoki Kawashima: Kosterlitz-Thouless transition of quantum XY model in two dimensions, Journal of Physical Society of Japan 67 (1998) 2768-2776.
    DOI: 10.1143/JPSJ.67.2768
  32. Kenji Harada, Matthias Troyer and Naoki Kawashima: The Two-Dimensional S=1 Quantum Heisenberg Antiferromagnet at Finite Temperatures, Journal of Physical Society of Japan 67 (1998) 1130-1133.
    DOI: 10.1143/JPSJ.67.1130
  33. Kenji Harada and Naoki Kawashima: Universal jump in helicity modulus of the two-dimensional quantum XY model, Physical Review B 55 (1997) 11949(R)-11952(R).
    DOI: 10.1103/PhysRevB.55.R11949

Proceedings

  1. Kenji Harada, "Tensor Network Studies of Quantum Frustrated Magnets",
    JPS Conf. Proc. 3 , 014031 (2014) [7 pages],
    Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2013).
    DOI: 10.7566/JPSCP.3.014031
  2. Mitsuaki Tsukamoto, Kenji Harada, Naoki Kawashima, "Quantum Monte Carlo Simulation of S=1/2 Heisenberg model with Four Spin Interaction",
    Proceedings of the 25th International Conference on Low Temperature Physics (Amsterdams, The Netherlands, 2008), Journal of Physics: Conference Series 150 (2009), 042218.
  3. Kenji Harada, Naoki Kawashima and Matthias Troyer, "Phase Diagram of the S=1 Bilinear Biquadratic Model",
    Proceedings of The 24th International Conference on Low Temperature Physics(LT24) (Florida, USA, 2005), 850 (2006), 1085-1086 (The AIP Conference Proceedings Series).
  4. Kenji Harada, "Quantum World-line Monte Carlo Method with Non-binary Loops and Its Application",
    Proceedings of The 18th Annual Workshop on Recent Developments of Computer Simulation Studies in Condensed Matter Physics (Athens, USA, 2005), 105 (2006), 13-26 (Springer Proceedings in Physics).
  5. Kenji Harada and Naoki Kawashima, "Quadrupolar order in the quantum XY model with cubic anisotropy", Order and Disorder in Quantum Spin Systems: Proceedings of the 16th Nishinomiya Yukawa Memorial Symposium and the Yukawa Institute for Theoretical Physics Workshop on Order, Disorder and Dynamics in Quantum Spin Systems, Progress of Theoretical Physics Supplement 145 (2002) 194-199.
    DOI: 10.1143/PTPS.145.194

Talks

  1. (INVITED TALK)Tensor renormalization group study of the non-equilibrium critical fixed point of the one-dimensional contact process, The 15th Asia Pacific Physics Conference (APPC15), August 26, 2022 (Korea, online).
  2. "Universal spectrum structure on the nonequilibrium critical line of the one-dimensional Domany-Kinzel cellular automaton",
    StatPhys seminar, May 31, 2021 (University of Tokyo, Hongo, Japan).
  3. (INVITED TALK)"Tensor network technique for stochastic process",
    Computational Approaches to Quantum Many-body Problems (CAQMP2019), July 17, 2019 (ISSP, Kashiwa, Japan).
  4. (INVITED TALK)"Entropy of the (1+1)-dimensional directed percolation",
    Tensor Network States: Algorithms and Applications (TNSAA) 2018-2019, Dec. 5, 2018 (R-CCS Kobe, Japan).
  5. (INVITED TALK)"Entanglement branching operator",
    Novel Quantum States in Condensed Matter 2017, Nov. 6, 2017 (YITP, Kyoto, Japan).
  6. (INVITED TALK)"General Entanglement Branching in a Tensor Network",
    Fourth Workshop on Tensor Network States: Algorithms and Applications, Dec. 14, 2016 (National Center for Theoretical Sciences, Hsinchu, Taiwan).
  7. (INVITED TALK)"Branching and tensor network",
    International Workshop on Tensor Networks and Quantum Many-Body Problems (TNQMP2016), June 27, 2016(ISSP, Kashiwa, Chiba).
  8. "Quantum Monte Carlo study of Quantum Criticality on SO(N) Bilinear-biquadratic Chains",
    International Workshop on New Frontier of Numerical Methods for Many-Body Correlations ― Methodologies and Algorithms for Fermion Many-Body Problems, Feb. 18, 2015 (Hongo Campus, The University of Tokyo) (Japan).
  9. (INVITED TALK)"Quantum Monte Carlo study of Quantum Criticality on SO(N) Bilinear Biquadratic Chains",
    the 9th International Conference on Computational Physics (ICCP9), Jan. 07, 2015 (National University of Singapore) (Singapore).
  10. (INVITED TALK)"MERA tensor network and its application on quantum frustrated magnets",
    10sor network workshop --- Field 2x5 joint workshop on new algorithms for quantum manybody problems ---, Nov. 25, 2014, (Kashiwa Future Center, Kashiwa, Chiba) (Japan).
  11. "Possibility of Deconfined Criticality in SU(N) Heisenberg Models at Small N",
    the YITP long-term Workshop "Novel Quantum States in Condensed Matter 2014" (NQS2014), Nov. 17, 2014(YITP, Kyoto university, Kyoto) (Japan).
  12. (INVITED TALK)"Deconfined quantum criticality in SU(N) Heisenberg models: Finite size scaling analysis based on Bayesian inference",
    Taipei Tensor Network Workshop 2013, Dec. 4, 2013 (National Taiwan University, Taipei)(Taiwan).
  13. (INVITED TALK)"Numerical study of quantum frustrated magnets using entanglement renormalization",
    International Workshop on Cooperative Quantum Dynamics and Its Control (CQDC’12), October 30, 2012 (Jeulich super computer center, Jeulich) (Germany).
  14. "Numerical study of incommensurability of the spiral state on spin-1/2 spatially anisotropic triangular antiferromagnets using entanglement renormalization",
    Conference on Computational Physics (CCP2012) for Physics, Chemistry, Biology, Engineering and related academic fields and industrial applications, October 15, 2012 (Kobe) (Japan).
  15. (INVITED TALK)"Bayesian Inference in the Scaling Analysis of Critical Phenomena",
    International Workshop on Recent Developments of Studies on Phase Transitions 2012, June 19, 2012 (University of Tokyo) (Japan).
  16. "Magnetic Structure of Ground States in Spatially Anisotropic Triangular Antiferromagnets",
    the 26th Nishinomiya-Yukawa Memorial International Workshop "Novel Quantum States in Condensed Matter 2011 (NQS2011)", November 8, 2011 (YITP, Kyoto University) (Japan).
  17. (INVITED TALK)"Entanglement renormalization on the triangular lattice",
    New Development of Numerical Simulations in Low-Dimensional Quantum Systems: From Density Matrix Renormalization Group to Tensor Network Formulations, Oct. 2010 (YITP, Kyoto University) (Japan).
  18. (INVITED TALK)"Entanglement renormalization of quantum frustrated magnets",
    Japan-Swiss Joint Workshop: New Trends in Theory of Correlated Materials, Aug. 2010 (Chiba, Japan).
  19. (INVITED TALK)"Multi-scale Entanglement Renormalization on a Triangular Lattice",
    Miniworkshop on Tensor Network Based Numerical Methods (Numerical Methods in Strongly Correlated Physics), May 28, 2010 (Nathional Center for Theoretical Sciences, National Tsing Hua University) (Hsinchu, Taiwan).
  20. "Quadrupolar order in the bilinear-biquadratic model",
    May 25, 2010 (Academia Sinica) (Taipei, Taiwan).
  21. (INVITED TALK)"Multi-scale entanglement renormalization of the spin-1/2 Heisenberg model on a triangular lattice",
    Workshop on Matrix Product State Formulation and Density Matrix Renormalization Group Simulations (MPS and DMRG), August 13, 2009 (Oxford Kobe Institute) (Kobe, Japan).
  22. "Quantum Monte Carlo simulations of quantum S=1 spin models with bi-quadratic interactions",
    Supercomputing in Solid State Physics 2009, February 18, 2009 (ISSP, Univ. of Tokyo) (Kashiwa, Japan).
  23. "Monte Carlo Study of Quantum Phase Transition in the Quasi-One-Dimensional SU(N) model",
    Symposium "Topological Aspects of Solid State Physics" (Poster), June 24, 2008 (YITP, Kyoto Univ.).
  24. "Monte Carlo Study of Quantum Phase Transition in the Quasi-One-Dimensional SU(N) model",
    The 1st International Conference of the Grand Challenge to Next-Generation Integrated Nanoscience (Poster), June 6, 2008 (ISSP, Univ. of Tokyo) (Kashiwa, Japan).
  25. "Quantum Phase Transition between Two Ordered Phases with Unrelated Symmetries",
    International Workshop and Symposium on Computational Approaches to Quantum Critical Phenomena, August 9, 2006 (ISSP, Univ. of Tokyo) (Kashiwa, Japan).
  26. "Loop Algorithm with Non-binary Loops",
    International Workshop and Symposium on Computational Approaches to Quantum Critical Phenomena, August 2, 2006 (ISSP, Univ. of Tokyo) (Kashiwa, Japan).
  27. "Phase Diagram of the S=1 Bilinear Biquadratic Model",
    The 24th International Conference on Low Temperature Physics(LT24) (Poster), August 15, 2005 (Florida, USA).
  28. (INVITED TALK)"Quantum World-line Monte Carlo Method with Non-Binary Loops",
    The 18th Annual Workshop on Recent Developments of Computer Simulation Studies in Condensed Matter Physics, March 8, 2005 (Univ. of Georgia) (Athens, USA).

Book, article

  1. Book "Advanced Mathematical Science for Mobility Society" Chapter 5 "Application of Tensor Network Formalism for Processing Tensor Data", Kenji Harada, Hiroaki Matsueda, and Tsuyoshi Okubo, Springer(2024), ISBN 978-981-99-9771-8, ISBN 978-981-99-9772-5 (eBook)(open access).