See also arXiv and Google Scholar.

Preprints

1. Y. Suzuki, Y. Kawase, Y. Masumura, Y. Hiraga, M. Nakadai, J. Chen, K. M. Nakanishi, K. Mitarai, R. Imai, S. Tamiya, T. Yamamoto, T. Yan, T. Kawakubo, Y. O. Nakagawa, Y. Ibe, Y. Zhang, H. Yamashita, H. Yoshimura, A. Hayashi, K. Fujii,
   Qulacs: a fast and versatile quantum circuit simulator for research purpose,
   (arXiv: 2011.13524)

Articles (peer-reviewed journal)

1. J. Takahashi, R. Imai, E. Nakano, and K. Iida,
   Bose polaron in spherical trap potentials: Spatial structure and quantum depletion,
   Phys. Rev. A 100, 023624 (2019).
   (arXiv: 1904.08799)

2. R. Imai and Y. Yamanaka,
   Dynamical Properties of the Finite-size Dicke Model Coupled to a Thermal Reservoir,
   J. Phys. Soc. Jpn. 88, 024401 (2019).
   (arXiv: 1810.05888)

3. R. Imai and Y. Yamanaka,
   Stability of symmetry breaking states in finite-size Dicke model with photon leakage,
   Phys. Lett. A, 382, 3333 (2018).
   (arXiv: 1801.05954)

Proceedings (peer-reviewed)

1. R. Imai, J. Takahashi, T. Oyama, Y. Yamanaka,
   Semiclassical analysis of driven-dissipative excitonic condensation,
   AIP Conference Proceedings 2319, 070006 (2021).
   

Articles (others)

1. 今井良輔,
   熱浴と接触する系に対する非平衡Thermo Field Dynamicsと射影演算子法,
   物性研究・電子版 Vol. 4, No. 2, 042601 (2015).