Hiroki Takahashi

Hiroki Takahashi
Assistant Professor
Ph.D in Quantum Optics (University of Tokyo)
Master in Applied Physics (University of Tokyo)

Hiroki was born, raised and nurtured in Japan during his youth. In his master and Ph.D, he worked on quantum optics involving squeezed light, Schrödinger’s kittens and tons of optical mirrors. After that he decided to try his luck in the United Kingdom where he also started new research about ion trapping and cavity QED. After turbulent but enjoyable eight and half years in the UK, he returned to Japan in one piece. Then at University of Tokyo he experienced research using superconducting Josephson circuits. Upon joining OIST, he switched his research subject back to the more experienced ion trapping with good memory of transmon qubits in his mind.

Professional Experience

  • PRESTO Researcher, University of Sussex (2010-2014)
  • Senior Research Assistant, University of Sussex (2014-2018)
  • Project Research Associate, University of Tokyo (2018-2019)
  • Specially Appointed Associate Professor, Osaka University (2019-2020)


  • Marie-Curie Post-doctoral fellowship (2009-2010)
  • PRESTO research grant (2010-2014)

Selected Publications

  • Hiroki Takahashi, Ezra Kassa, Costas Christoforou, and Matthias Keller, “Strong coupling of a single ion to an optical cavity", Physical Review Letters 124, 013602 (2020).
  • Thomas Walker, Koichiro Miyanishi, Rikizo Ikuta, Hiroki Takahashi, Samir Vartabi Kashanian, Yoshiaki Tsujimoto, Kazuhiro Hayasaka, Takashi Yamamoto, Nobuyuki Imoto, and Matthias Keller, “Long-distance single photon transmission from a trapped ion via quantum frequency conversion", Physical Review Letters 120, 203601 (2018).
  • Hiroki Takahashi, Ezra Kassa, Costas Christoforou, and Matthias Keller, “Cavity-induced anticorrelated photon-emission rates of a single ion", Physical Review A 96, 023824 (2017).
  • Hiroki Takahashi, Pedro Nevado and Matthias Keller, “Mølmer-Sørensen entangling gate for cavity QED systems", Journal of Physics B 50, 195501 (2017).
  • Hiroki Takahashi, Jack Morphew, Fedja Orucevic, Atsushi Noguchi, Ezra Kassa and Matthias Keller “Novel laser machining of optical fibers for long cavities with low birefringence" Optics Express, 22, 31317 (2014).
  • Hiroki Takahashi, Alex Wilson, Andrew Riley-Watson, F. Orucevic, Nicholas Seymour-Smith, Matthias Keller and Wofgang Lange, “An integrated fiber trap for single-ion photonics" New Journal of Physics, 15, 053011 (2013).
  • Hiroki Takahashi, Jonas S. Neergaard-Nielsen, Makoto Takeuchi, Masahiro Takeoka, Kazuhiro Hayasaka, Akira Furusawa, and Masahide Sasaki, “Entanglement distillation from Gaussian input states", Nature Photonics, 4, 178 (2010).
  • Hiroki Takahashi, Kentaro Wakui, Shigenari Suzuki, Masahiro Takeoka, Kazuhiro Hayasaka, Akira Furusawa, and Masahide Sasaki, “Generation of large-amplitude coherent-state superposition via ancilla-assisted photon-subtraction", Physical Review Letters, 101, 233605 (2008).