Publications

Papers

1. “Fast and accurate rare-event simulation by Markov chain Monte Carlo for general quantum codes”
   J. Haruna and K. Murakami
   arXiv:2610.35498 (2026)
2. “Homological origin of transversal implementability of logical diagonal gates in quantum CSS codes”
   J. Haruna
   PTEP 2026, No.8, 083A03 (2026), arXiv:2602.14499
3. “Note on Logical Gates by Gauge Field Formalism of Quantum Error Correction”
   J. Haruna
   PTEP 2026, No.7, 073B12 (2026), arXiv:2511.15224
4. “Hierarchical Quantum Error Correction with Hypergraph Product Code and Rotated Surface Code”
   J. Haruna and K. Fujii
   PTEP 2025, No.10, 103A03 (2025), arXiv:2505.18592
5. “Functional renormalization group analysis of the O(3) nonlinear sigma model and non-Abelian bosonization duality”
   J. Haruna, K. Shimizu and M. Yamada
   Phys. Rev. D 111, No.4, 045012 (2025), arXiv:2405.14627
6. “Gradient Flow Exact Renormalization Group for Scalar Quantum Electrodynamics”
   J. Haruna and M. Yamada
   JHEP 05, 291 (2024), arXiv:2312.15673
7. “End-to-end complexity for simulating the Schwinger model on quantum computers”
   K. Sakamoto, H. Morisaki, J. Haruna, E. Itou, K. Fujii and K. Mitarai
   Quantum 8, 1474 (2024), arXiv:2311.17388
8. “Nonperturbative aspects of two-dimensional TT-deformed scalar theory from functional renormalization group”
   J. Liu, J. Haruna and M. Yamada
   Phys. Rev. D 109, No.6, 065016 (2024), arXiv:2309.15584
9. “Fixed Point Structure of Gradient Flow Exact Renormalization Group for Scalar Field Theories”
   Y. Abe, Y. Hamada and J. Haruna
   PTEP 2022, No.3, 033B03 (2022), arXiv:2201.04111
10. “Path integral approach to universal dynamics of reservoir computers”
    J. Haruna, R. Toshio and N. Nakano
    Phys. Rev. E 107, No.3, 034306 (2023), arXiv:2112.01886
11. “Burgers equation vs. large N limit in TT-deformed O(N) vector model”
    J. Haruna, K. Sakai and K. Yoshida
    Nucl. Phys. B 971, 115499 (2021), arXiv:2104.05431
12. “Large N analysis of TT-deformation and unavoidable negative-norm states”
    J. Haruna, T. Ishii, H. Kawai, K. Sakai and K. Yoshida
    JHEP 04, 127 (2020), arXiv:2002.01414
13. “Weak scale from Planck scale: Mass scale generation in a classically conformal two-scalar system”
    J. Haruna and H. Kawai
    PTEP 2020, No.3, 033B01 (2020), arXiv:1905.05656

Thesis

• Ph.D. Thesis
  “Gradient Flow Exact Renormalization Group for Scalar Field Theories”
  Doctor of Science, Mar. 2023, Kyoto University [KURENAI]
• Master Thesis
  “Large N極限による場の量子論の非摂動的解析とプランクスケールの物理”
  Master of Science, Mar. 2020, Kyoto University, Supervisor: Prof. Hikaru Kawai

Lecture note

• Quantum Error Correction (v1)
  “New computational methods in quantum field theory 2026”, RIKEN Wako Campus, 26th-28th Jan. 2026

Software and data

• rare-event-mcmc-qec (GitHub, MIT)
  J. Haruna and K. Murakami. Sampler, codes and decoders, cluster job scripts, simulation outputs and reference estimates behind arXiv:2610.35498.
• mcmc4qec (GitHub, MIT)
  Python library for estimating logical error rates of quantum error-correcting codes with failure-conditioned MCMC and BAR splitting, with exact enumeration and direct Monte Carlo for comparison. Pre-alpha.
• bockstein-gate-check (GitHub, MIT)
  Feasibility checker for transversal diagonal logical gates in CSS codes. Prototype backing arXiv:2602.14499.
• Data and code for “Hierarchical Quantum Error Correction with Hypergraph Product Code and Rotated Surface Code” (Zenodo, CC BY 4.0)
  J. Haruna and K. Fujii. Notebooks, scripts, parity check matrices and logical error rates for arXiv:2505.18592.
• PIReservoir (GitHub, MIT)
  Numerical code for “Path integral approach to universal dynamics of reservoir computers”, arXiv:2112.01886.
• GLMCC (GitHub)
  Python code for the GLM-based cross-correlation method to estimate neuronal connectivity (with R. Kobayashi and S. Shinomoto).