Publications

Original papers

Ryutaro Ohira, Shota Kume, Kyoichi Takayama, Silpa Muralidharan, Hiroki Takahashi, Kenji Toyoda: Blockade of phonon hopping in trapped ions in the presence of multiple local phonons
Phys. Rev. A 103, 012612 (2021).

Masaya Tamura, Takashi Mukaiyama, Kenji Toyoda: Quantum walks of a phonon in trapped ions
Phys. Rev. Lett. 124, 200501 (2020).

Ryutaro Ohira, Takashi Mukaiyama, and Kenji Toyoda: Breaking rotational symmetry in a trapped-ion quantum tunneling rotor
Phys. Rev. A 101, 022106 (2020).

Ryutaro Ohira, Takashi Mukaiyama, and Kenji Toyoda: Phonon-number-resolving detection of multiple local phonon modes in trapped ions
Phys. Rev. A 100, 060301(R) (2019).

Miho Fujieda, Tetsuya Ido, Hidekazu Hachisu, Tadahiro Gotoh, Hiroshi Takiguchi, Kazuhiro Hayasaka, Kenji Toyoda, Kenji Yonegaki, Utako Tanaka, and Shinji Urabe: “Frequency Measurement System of Optical Clocks Without a Flywheel Oscillator”
IEEE Trans. Ultrason., Ferroelect., Freq. Control 63/12, 2231-2236 (2016).

Kenji Toyoda, Ryoto Hiji, Atsushi Noguchi & Shinji Urabe: “Hong-Ou-Mandel interference of two phonons in trapped ions”
Nature 527, 74-77 (2015).

Atsushi Noguchi, Yutaka Shikano, Kenji Toyoda & Shinji Urabe: “Aharonov-Bohm effect in the tunnelling of a quantum rotor in a linear Paul trap”
Nature Comm. 5, 3868 (2014).

Kenji Toyoda, Yuta Matsuno, Atsushi Noguchi, Shinsuke Haze and Shinji Urabe: Experimental Realization of a Quantum Phase Transition of Polaritonic Excitations
Phys. Rev. Lett. 111, 160501 (2013).
K. Toyoda, K. Uchida, A. Noguchi, S. Haze, and S. Urabe: Realization of holonomic single-qubit operations
Phys. Rev. A 87, 052307 (2013).

Atsushi Noguchi, Kenji Toyoda, Shinji Urabe: Generation of Dicke States with Phonon-Mediated Multi-level Stimulated Raman Adiabatic Passage
Phys. Rev. Lett. 109, 260502 (2012).
Atsushi Noguchi, Shinsuke Haze, Kenji Toyoda, Shinji Urabe: Generation of a Decoherence-Free Entangled State Using a Radio-Frequency Dressed State
Phys. Rev. Lett. 108, 060503 (2012).
Shinsuke Haze, Yusuke Tateishi, Atsushi Noguchi, Kenji Toyoda, and Shinji Urabe: Observation of phonon hopping in radial vibrational modes of trapped ions
Phys. Rev. A. 85, 031401(R) (2012).

Takao Ohno, Kensuke Uchida, Shinsuke Haze, Kenji Toyoda, Shinji Urabe: Realization of fast Rabi oscillations in RF magnetic resonance of ground Zeeman state of 40Ca+
Jpn. J. Appl. Phys 50,122801 (2011).
S. Haze, T. Ohno, K. Toyoda and S. Urabe: Measurement of the coherence time of the ground-state Zeeman states in 40Ca+
Appl. Phys. B 105, 761 (2011).
T. Watanabe, S. Nomura, K. Toyoda, and S. Urabe: Sideband Excitation of Trapped Ions by Rapid Adiabatic Passage for Manipulation of Motional State
Phys. Rev. A 84, 033412 (2011).
K.Toyoda, T.Watanabe, K.Kimura, S.Nomura, S.Haze, S.Urabe: Generation of Dicke states using adiabatic passage
Phys. Rev. A 83, 022315 (2011).

Kenji Toyoda, Shinsuke Haze, Rekishu Yamazaki, and Shinji Urabe: Quantum gate using qubit states separated by terahertz, Phys. Rev. A 81, 032322 (2010).
S.Haze, Y.Senokuchi, R.Yamazaki, K.Toyoda, S.Urabe: Phase-locked light source with low-phase noise for manipulating terahertz-separated metastable states in 40Ca+, Appl. Phys. B 101, 547 (2010).
Shinsuke HAZE, Kenji TOYODA, Shinji URABE: Manipulation between the Metastable D States of A Single 40Ca+ The Review of Laser Engineering 38/7,512-516 (2010).

Shinsuke Haze, Rekishu Yamazaki, Kenji Toyoda, Shinji Urabe: Measurement and compensation of optical Stark shift for manipulating the terahertz-separated states in 40Ca+, Phys. Rev. A 80, 053408 (2009).
K. Toyoda, H. Shiibara, S. Haze, R. Yamazaki, S. Urabe: Experimental study of the coherence of a terahertz-separated metastable-states qubit in 40Ca+, Phys. Rev. A 79, 023419 (2009).

H.Sawamura, K.Kanda, R.Yamazaki, K.Toyoda, S. Urabe: Optimum parameters for sideband cooling of a 40Ca+ ion, Appl. Phys. B 93, 381 (2008).
Rekishu Yamazaki, Ken-ichi Kanda, Fumihiko Inoue, Kenji Toyoda, Shinji Urabe: Robust generation of superposition states, Phys. Rev. A 78,023808 (2008).
Rekishu Yamazaki, Hideyuki Sawamura, Kenji Toyoda, Shinji Urabe: Stimulated Raman spectroscopy and the determination of the D-fine-structure level separation in 40Ca+, Phys. Rev. A 77, 012508 (2008).

Rekishu Yamazaki, Toshiki Iwai, Kenji Toyoda, and Shinji Urabe: Phase-locked laser system for a metastable states qubit in 40Ca+, Opt. Lett. 32, 2085 (2007).
Hideyuki Sawamura, Kenji Toyoda, Shinji Urabe: Optimization of Doppler Cooling of a Single 40Ca+ Ion, Jpn. J. Appl. Phys. 46, 1713 (2007).

K. Toyoda, Y. Kubota, T. Okano, S. Urabe: Ultraviolet diode laser system based on the resonant optical feedback method with the capability of fast continuous sweep, Appl. Phys. B 82, 25 (2006).

H. Sawamura, H. Kitamura, K. Toyoda, and S. Urabe: Observation of motional sidebands in single 40Ca+ ions with improved detection efficiency, Appl. Phys. B 80, 1011 (2005).

Ryutaro Ohira, Shota Kume, Hiroki Takahashi, and Kenji Toyoda: Polariton blockade in the Jaynes-Cummings-Hubbard model with trapped ions
arXiv:2103.05253