岡﨑 研究室 (Okazaki group)

[1] Temporal Evolution and Fluence Dependence of Band Structure in Photoexcited Ta2Ni_0.9Co_0.1Se₅ Probed by Time- and Angle-Resolved Photoemission Spectroscopy
Yu Takahashi, Takeshi Suzuki, Masaki Hattori, Mario Okawa, Hidenori Takagi, Naoyuki Katayama, Hiroshi Sawa, Minoru Nohara, Yigui Zhong, Kecheng Liu, Teruto Kanai, Jiro Itatani, Shik Shin, Kozo Okazaki, and Takashi Mizokawa
Journal of the Physical Soicety of Japan, in press.
DOI:

[2] Nodeless electron pairing in CsV3Sb5-derived kagome superconductors
Yigui Zhong, Jinjin Liu, Xianxin Wu, Zurab Guguchia, J.-X. Yin, Akifumi Mine, Yongkai Li, Sahand Najafzadeh, Debarchan Das, Charles Mielke III, Rustem Khasanov, Hubertus Luetkens, Takeshi Suzuki, Kecheng Liu, Xinloong Han, Takeshi Kondo, Jiangping Hu, Shik Shin, Zhiwei Wang*, Xun Shi*, Yugui Yao, and Kozo Okazaki*
Nature, in press.
DOI: 10.1038/s41586-023-05907-x

[3] Testing electron–phonon coupling for the superconductivity in kagome metal CsV₃Sb₅
Yigui Zhong, Shaozhi Li, Hongxiong Liu, Yuyang Dong, Kohei Aido, Yosuke Arai, Haoxiang Li, Weilu Zhang, Youguo Shi, Ziqiang Wang, Shik Shin, H. N. Lee, H. Miao*, Takeshi Kondo*, and Kozo Okazaki*
Nature Communications 14, 1945 (2023).
DOI: 10.1038/s41467-023-37605-7

[4] Quasi One-Dimensional Band Structure of Photoinduced Semimetal Phase of Ta₂Ni_1-xCo_xSe₅ (x = 0.0 and 0.1)
Takumi Mitsuoka, Yu Takahashi, Takeshi Suzuki , Mario Okawa , Hidenori Takagi, Naoyuki Katayama, Hiroshi Sawa, Minoru Nohara, Mari Watanabe, Jiadi Xu, Qianhui Ren, Masami Fujisawa, Teruto Kanai, Jiro Itatani, Kozo Okazaki , Shik Shin, and Takashi Mizokawa
Journal of the Physical Soicety of Japan 92, 023703 (2023).
DOI: 10.7566/JPSJ.92.023703

[5] Direct observation of multiple conduction-band minima in high-performance thermoelectric SnSe
Mario Okawa*, Yuka Akabane, Mizuki Maeda, Gangjian Tan, Li-Dong Zhao, Mercouri G. Kanatzidis, Takeshi Suzuki, Mari Watanabe, Jiadi Xu, Qianhui Ren, Masami Fujisawa, Teruto Kanai, Jiro Itatani, Shik Shin, Kozo Okazaki, Naurang L. Saini, Takashi Mizokawa
Scripta Materialia 223, 115081 (2023).
DOI: 10.1016/j.scriptamat.2022.115081

[6] Coexistence of Bulk-Nodal and Surface-Nodeless Cooper Pairings in a Superconducting Dirac Semimetal
Xian P. Yang*, Yigui Zhong, Sougata Mardanya, Tyler A. Cochran, Ramakanta Chapai, Akifumi Mine, Junyi Zhang*, Jaime Sánchez-Barriga, Zi-Jia Cheng, Oliver J. Clark, Jia-Xin Yin, Joanna Blawat, Guangming Cheng, Ilya Belopolski, Tsubaki Nagashima, Sahand Najafzadeh, Shiyuan Gao, Nan Yao, Arun Bansil, Rongying Jin, Tay-Rong Chang, Shik Shin, Kozo Okazaki, and M. Zahid Hasan*
Physical Review Letters 130, 046402 (2023).
DOI: 10.1103/PhysRevLett.130.046402

[3] Tunable vortex Majorana modes controlled by strain in homogeneous LiFeAs
Wenyao Liu, Quanxin Hu, Xiancheng Wang, Yigui Zhong, Fazhi Yang, Lingyuan, Kong, Lu Cao, Geng Li, Yi Peng, Kozo Okazaki,Takeshi Kondo, Changqing Jin, Fuchun Zhang, Jinpeng Xu*, Hong-Jun Gao*, and Hong Ding*
Quantum Frontiers 1, 20 (2022).
DOI: 10.1007/s44214-022-00022-w

[2] Photo-induced transient electronic states of 2H-NbSe₂ observed by time-resolved photoemission spectroscopy
Mari Watanabe, Takeshi Suzuki*, Takashi Someya, Yu Ogawa, Shoya Michimae, Masami Fujisawa, Teruto Kanai, Jiro Itatani, Tomohiko Saitoh, Shik Shin, and Kozo Okazaki*
J. Phys. Soc. Jpn. 91, 064703 (2022).
DOI: 10.7566/JPSJ.91.064703

[1] Environmental effects on layer-dependent dynamics of Dirac fermions in quasicrystalline bilayer graphene
Y. Zhao, T. Suzuki, T. Iimori, H.-W. Kim, J. R. Ahn, M. Horio, Y. Sato, Y. Fukaya, T. Kanai, K. Okazaki, S. Shin, S. Tanaka, F. Komori, H. Fukidome and I. Matsuda
Phys. Rev. B 105, 115301 (2022).
DOI: 10.1103/PhysRevB.105.115304

[4] Ultrafast optical stress on BaFe₂As₂
Takeshi Suzuki, Yuya Kubota, Takahiro Shimojima, Asuka Nakamura, Ko Takubo, Suguru Ito, Kohei Yamamoto, Hikari Sato, Hidenori Hiramatsu, Hideo Hosono, Tadashi Togashi, Makina Yabashi, Hiroki Wadati, Iwao Matsuda, Shik Shin, and Kozo Okazaki
Phys. Rev. Res. 3, 033222 (2021).
DOI: 10.1103/PhysRevResearch.3.033222

[3] Discovery of Pressure-Induced Superconductivity in an Excitonic Insulator
Kozo Okazaki
JPSJ News and Comments 18, 11 (2021).
DOI: 10.7566/JPSJNC.18.11

[2] HHG-laser-based time- and angle-resolved photoemission spectroscopy of quantum materials
Takeshi Suzuki, Shik Shin, and Kozo Okazaki
J. Electron Spectrosc. Relat. Phenom. 251, 147105 (2021).
DOI: 10.1016/j.elspec.2021.147105

[1] Detecting electron-phonon couplings during photo-induced phase transition
Takeshi Suzuki, Yasushi Shinohara, Yangfan Lu, Mari Watanabe, Jiadi Xu, Kenichi L. Ishikawa, Hide Takagi, Minoru Nohara, Naoyuki Katayama, Hiroshi Sawa, Masami Fujisawa, Teruto Kanai, Jiro Itatani, Takashi Mizokawa, Shik Shin, and Kozo Okazaki
Phys. Rev. B 103, L121105 (2021).
DOI: 10.1103/PhysRevB.103.L121105

[4] Photoinduced phase transition from excitonic insulator to topological nodal semimetal
Takumi Mitsuoka, Takeshi Suzuki, Hide Takagi, Naoyuki Katayama, Hiroshi Sawa, Minoru Nohara, Mari Watanabe, Jiadi Xu, Qianhui Ren, Masami Fujisawa, Teruto Kanai, Jiro Itatani, Sik Shin, Kozo Okazaki, Takashi Mizokawa
J. Phys. Soc. Jpn. 89, 124703 (2020).
DOI: 10.7566/JPSJ.89.124703

[3] Bose–Einstein condensation superconductivity induced by disappearance of the nematic state
Takahiro Hashimoto, Yuichi Ota, Akihiro Tsuzuki, Tsubaki Nagashima, Akiko Fukushima, Shigeru Kasahara, Yuji Matsuda, Kohei Matsuura, Yuta Mizukami, Takasada Shibauchi, Shik Shin, and Kozo Okazaki*
Sci. Adv. 6, eabb9052 (2020).
DOI: 10.1126/sciadv.abb9052

[2] Massive suppression of proximity pairing in topological (Bi1-xSbx)2Te3 films on niobium
Joseph A. Hlevyack, Sahand Najafzadeh, Meng-Kai Lin, Takahiro Hashimoto, Tsubaki Nagashima, Akihiro Tsuzuki, Akiko Fukushima, Cédric Bareille, Yang Bai, Peng Chen, Ro-Ya Liu, Yao Li, David Flötotto, José Avila, James N. Eckstein, Shik Shin, Kozo Okazaki*, and T.-C. Chiang*
Phys. Rev. Lett. 124, 236402 (2020).
DOI: 10.1103/PhysRevLett.124.236402

[1] Devil's staircase transition of the electronic structures in CeSb
Kenta Kuroda*, Y. Arai, N. Rezaei, S. Kunisada, S. Sakuragi, M. Alaei, Y. Kinoshita, C. Bareille, R. Noguchi, M. Nakayama, S. Akebi, M. Sakano, K. Kawaguchi, M. Arita, S. Ideta, K. Tanaka, H. Kitazawa, K. Okazaki, M. Tokunaga, Y. Haga, S. Shin, H. S. Suzuki, R. Arita, and Takeshi Kondo
Nat. Commun. 11, 2888 (2020).
DOI: 10.1038/s41467-020-16707-6

[6] Symmetry-breaking and spin-blockage effects on carrier dynamics in single-layer tungsten diselenide
Ro-Ya Liu, Meng-Kai Lin, Peng Chen, Takeshi Suzuki, Pip C. J. Clark, Nathan Lewis, Cephise Cacho, Emma Springate, Chia-Seng Chang, Kozo Okazaki, Wendy Flavell*, Iwao Matsuda*, Tai-Chang Chiang*
Phys. Rev. B, 100, 214309 (2019).
DOI: 10.1103/PhysRevB.100.214309

[5] Orbital-dependent Superconducting Gap in SrFe₂(As_0.65P_0.35)₂ Studied by Angle-resolved Photoemission Spectroscopy
Hauto Suzuki, T. Kobayashi, S. Miyasaka, Kozo Okazaki, Teppei Yoshida, Msafumi Horio, L. C. C. Ambolode II, Y. Ota, H. Yamamoto, S. Shin, M. Hashimoto, D. H. Lu, Z.-X. Shen, S. Tajima, and A. Fujimori
Sci. Rep. 9, 16418 (2019).
DOI: 10.1038/s41598-019-52887-y

[4] Ultrafast Unbalanced Electron Distributions in Quasicrystalline 30° Twisted Bilayer Graphene
Takeshi Suzuki*, Takushi Iimori, Sung Joon Ahn, Yuhao Zhao, Mari Watanabe, Jiadi Xu, Masami Fujisawa, Teruto Kanai, Nobuhisa Ishii, Jiro Itatani, Kento Suwa, Hirokazu Fukidome, Satoru Tanaka, Joung Real Ahn, Kozo Okazaki, Shik Shin, Fumio Komori*, Iwao Matsuda*
ACS Nano 13, 11981-11987 (2019).
DOI: 10.1021/acsnano.9b06091

[3] Photo-induced possible superconducting state with long-lived disproportionateband filling in FeSe
Takeshi Suzuki*, Takashi Someya, Takahiro Hashimoto, Shoya Michimae, Mari Watanabe, Masami Fujisawa, Teruto Kanai, Nobuhisa Ishii, Jiro Itatani, Shigeru Kasahara, Yuji Matsuda, Takasada Shibauchi, Kozo Okazaki*, and Shik Shin*
Commun. Phys. 2, 115 (2019).
DOI: 10.1038/s42005-019-0219-4

[2] d-wave superconducting gap observed in the protect-annealed electron-doped cuprate superconductors Pr_1.3-xLa_0.7Ce_xCuO₄
M. Horio*, K. Koshiishi, S. Nakata, K. Hagiwara, Y. Ota, K. Okazaki, S. Shin, S. Ideta, K. Tanaka, A. Takahashi, T. Ohgi, T. Adachi, Y. Koike, and A. Fujimori
Phys. Rev. B 100, 054517 (2019).
DOI: 10.1103/PhysRevB.100.054517

[1] Multiple topological states in iron-based superconductors
Peng Zhang*, Zhijun Wang, Xianxin Wu, Koichiro Yaji, Yukiaki Ishida, Yoshimitsu Kohama, Guangyang Dai, Yue Sun, Cedric Bareille, Kenta Kuroda, Takeshi Kondo, Kozo Okazaki, Koichi Kindo, Xiancheng Wang, Changqing Jin, Jiangping Hu, Ronny, Thomale, Kazuki Sumida, Shilong Wu, Koji Miyamoto, Taichi Okuda, Hong Ding, G.D. Gu, Tsuyoshi Tamegai, Takuto Kawakami, Masatoshi Sato, and Shik Shin*
Nat. Phys. 15, 41-47 (2019).
DOI: 10.1038/s41567-018-0280-z

[6] Photo-induced semimetallic states realised in electron-hole coupled insulators
Kozo Okazaki*, Yu Ogawa, Takeshi Suzuki, Takashi Yamamoto, Takashi Someya, Shoya Michimae, Mari Watanabe, Yangfan Lu, Minoru Nohara, Hidenori Takagi, Naoyuki Katayama, Hiroshi Sawa, Masami Fujisawa, Teruto Kanai, Nobuhisa Ishii, Jiro Itatani, Takashi Mizokawa, and Shik Shin*
Nat. Commun. 9, 4322 (2018).
DOI: 10.1038/s41467-018-06801-1

[5] Superconducting pairing of topological surface states in bismuth selenide films on niobium
David Flötotto*, Yuichi Ota, Yang Bai, Can Zhang, Kozo Okazaki, Akihiro Tsuzuki, Takahiro Hashimoto, James N. Eckstein, Shik Shin, and Tai-Chang Chiang*
Sci. Adv. 4, eaar7214 (2018).
DOI: 10.1126/sciadv.aar7214

[4] Experimental observation of topological superconductivity on iron-based superconductor
Peng Zhang*, Koichiro Yaji, Takahiro Hashimoto, Yuichi Ota, Takeshi Kondo, Kozo Okazaki, Zhijun Wang, Jinsheng Wen, G. D. Gu, Hong Ding*, and Shik Shin*
Science 360, 182-186 (2018).
DOI: 10.1126/science.aan4596

[3] Antiphase Fermi-surface modulations accompanying displacement excitation in a parent compound of iron-based superconductors
Kozo Okazaki*, Hakuto Suzuki, Takeshi Suzuki, Takashi Yamamoto, Takashi Someya, Yu Ogawa, Masaru Okada, Masami Fujisawa, Teruto Kanai, Nobuhisa Ishi, Jiro Itatani, Masamichi Nakajima, Hiroshi Eisaki, Aatsuhi Fujimori, and Shik Shin*
Phys. Rev. B 97, 121107(R)/1-6 (2018).
DOI: 10.1103/PhysRevB.97.121107

[2] Superconducting gap anisotropy sensitive to nematic domains in FeSe
Takahiro Hashimoto, Yuichi Ota, Haruyoshi Q Yamamoto, Yuya Suzuki, Takahiro Shimojima, Shuntaro Watanabe, Chuangtian Chen, Shigeru Kasahara, Yuji Matsuda, Takasada Shibauchi, Kozo Okazaki, and Shik Shin
Nat. Commun. 9, 282/1-7 (2018).
DOI: 10.1038/s41467-017-02739-y

[1] Resonant magneto-optical Kerr effect measurement system using a high harmonic generation laser
Sh. Yamamoto, D. Oumbarek, M. Fujisawa, T. Someya, Y. Takahashi, T. Yamamoto, N. Ishiia, K. Yajia, S. Yamamoto, T. Kanai, K. Okazaki, M. Kotsugi, J. Itatani, S. Shin, I. Matsuda
J. Electron Spectrosc. Relat. Phenom. 222, 68-73 (2018).
DOI: 10.1016/j.elspec.2017.09.001

[5] Femtosecond to picosecond transient effects in WSe2 observed by pump-probe angle-resolved photoemission spectroscopy
Ro-Ya Liu, Yu Ogawa, Peng Chen, Kenichi Ozawa, Takeshi Suzuki, Masaru Okada, Takashi Someya, Yukiaki Ishida, Kozo Okazaki, Shik Shin, Tai-Chang Chiang, and Iwao Matsuda
Sci. Rep. 7, 15981/1-7 (2017).
DOI: 10.1038/s41598-017-16076-z

[4] Suppression of supercollision carrier cooling in high mobility graphene on SiC(0001)
Takashi Someya, Hirokazu Fukidome, Hiroshi Watanabe, Takashi Yamamoto, Masaru Okada, Hakuto Suzuki, Yu Ogawa, Takushi Iimori, Nobuhisa Ishii, Teruto Kanai, Keiichiro Tashima, Baojie Feng, Susumu Yamamoto, Jiro Itatani, Fumio Komori, Kozo Okazaki, Shik Shin, and Iwao Matsuda
Phys. Rev. B 95, 165303(1-7) (2017). Editors' Suggestion
DOI: 10.1103/PhysRevB.95.165303

[3] Unconventional superconductivity in the BiS2-based layered superconductor NdO_0.71F_0.29BiS₂
Yuichi Ota, Kozo Okazaki, Haruyoshi Q. Yamamoto, Takashi Yamamoto, Shuntaro Watanabe, Chuangtian Chen, Masanori Nagao, Satoshi Watauchi, Isao Tanaka, Yoshihiko Takano, and Shik Shin
Phys. Rev. Lett 118, 167002(1-6) (2017).
DOI: 10.1103/PhysRevLett.118.167002

[2] Ultrafast Melting of Spin DensityWave Order in BaFe₂As₂ Observed by Time- and Angle-Resolved Photoemission Spectroscopy with Extreme-Ultraviolet Higher Harmonic Generation
H. Suzuki, K. Okazaki, T. Yamamoto, T. Someya, M. Okada, K. Koshiishi, M. Fujisawa, T. Kanai, N. Ishii, M. Nakajima, H. Eisaki, K. Ono, H. Kumigashira, J. Itatani, A. Fujimori and S. Shin
Phys. Rev. B 95, 165112(1-6) (2017).
DOI: 10.1103/PhysRevB.95.165112

[1] Unusual nodal behaviors of the superconducting gap in the iron-based superconductor Ba(Fe_0.65Ru_0.35)₂As₂: Effects of spin-orbit coupling
L. Liu, K. Okazaki, T. Yoshida, H. Suzuki, M. Horio, L. C. C. Ambolode II, J. Xu, S. Ideta, M. Hashimoto, D. H. Lu, Z.-X. Shen, Y. Ota, S. Shin, M. Nakajima, S. Ishida, K. Kihou, C. H. Lee, A. Iyo, H. Eisaki, T. Mikami, T. Kakeshita, Y. Yamakawa, H. Kontani, S. Uchida, and A. Fujimori
Phys. Rev. B 95, 104504(1-5) (2017).
DOI: 10.1103/PhysRevB.95.104504

[1] Suppression of the antiferromagnetic pseudogap in the electron-doped high-temperature superconductor by "protect annealing"
M. Horio, T. Adachi, Y. Mori, A. Takahashi, T. Yoshida, H. Suzuki, L. C. C. Ambolode II, K. Okazaki, K. Ono, H. Kumigashira, H. Anzai, M. Arita, H. Namatame, M. Taniguchi, D. Ootsuki, K. Sawada, M. Takahashi, T. Mizokawa, Y. Koike, and A. Fujimori
Nat. Commun. 7, 10567(1-8) (2016).
DOI: 10.1038/ncomms10567

[5] Nonequilibrium electronic and phonon dynamics of Cu_0.17Bi₂Se₃ investigated by core-level and valence-band time-resolved photoemission spectroscopy
T. Yamamoto, Y. Ishida, R. Yoshida, M. Okawa, K. Okazaki, T. Kanai, A. Kikkawa, Y. Taguchi, T. Kiss, K. Ishizaka, N. Ishii, J. Itatani, S. Watanabe, Y. Tokura, T. Saitoh, and S. Shin
Phys. Rev. B 92, 121106(R).
DOI: 10.1103/PhysRevB.92.121106

[4] In-plane electronic anisotropy in the antiferromagnetic-orthorhombic phase of isovalent-substituted Ba(Fe_1−xRu_x)₂As₂
L. Liu, T. Mikami, S. Ishida, K. Koshiishi, K. Okazaki, T. Yoshida, H. Suzuki, M. Horio, L. C. C. Ambolode II, J. Xu, H. Kumigashira, K. Ono, M. Nakajima, K. Kihou, C. H. Lee, A. Iyo, H. Eisaki, T. Kakeshita, S. Uchida, and A. Fujimori,
Phys. Rev. B 92, 094503 (2015)
DOI: 10.1103/PhysRevB.92.094503

[3] Low-Temperature and High-Energy-Resolution Laser Photoemission Spectroscopy
Takahiro Shimojima, Kozo Okazaki, and Shik Shin
J. Phys. Soc. Jpn. 84, 072001 (2015) (Invited Review Paper).
DOI: 10.7566/JPSJ.84.072001

[2] Dependence of electron correlation strength in Fe_1+yTe_1-xSe_x on Se content
L. C. C. Ambolode II, K. Okazaki, M. Horio, H. Suzuki, L. Liu, S. Ideta, T. Yoshida, T. Mikami, T. Kakeshita, S. Uchida, K. Ono, H. Kumigashira, M. Hashimoto, D. -H. Lu, Z. -X. Shen, and A. Fujimori,
Phys. Rev. B 92, 035104 (2015).
DOI: 10.1103/PhysRevB.92.035104

[1] Reversed anisotropy of the in-plane resistivity in the antiferromagnetic phase of iron tellurides
L. Liu, T. Mikami, M. Takahashi, S. Ishida, T. Kakeshita, K. Okazaki, A. Fujimori, and S. Uchida,
Phys. Rev. B 91, 134502 (2015).
DOI: 10.1103/PhysRevB.91.134502

[5] Evidence of a universal relation between electron-mode coupling and T_c in Ba_1−xK_xFe₂As₂ superconductor from laser angle-resolved photoemission spectroscopy
W. Malaeb, T. Shimojima, Y. Ishida, T. Kondo, K. Okazaki, Y. Ota, K. Ohgushi, K. Kihou, C. H. Lee, A. Iyo, H. Eisaki, S. Ishida, M. Nakajima, S. Uchida, H. Fukazawa, T. Saito, Y. Kohori, and S. Shin
Phys. Rev. B 90, 195124(1-6) (2014).
DOI: 10.1103/PhysRevB.90.195124

[4] Strongly three-dimensional electronic structure and Fermi surfaces of SrFe₂(As_0.65P_0.35)₂: Comparison with BaFe₂(As_1-xP_x)₂
H. Suzuki, T. Kobayashi, S. Miyasaka, T. Yoshida, K. Okazaki, L. C. C. Ambolode, II, S. Ideta, M. Yi, M. Hashimoto, D. H. Lu, Z.-X. Shen, K. Ono, H. Kumigashira, S. Tajima, and A. Fujimori
Phys. Rev. B 89, 184513 (2014).
DOI: 10.1103/PhysRevB.89.184513

[3] Evidence for excluding the possibility of d-wave superconducting-gap symmetry in Ba-doped KFe₂As₂
Y. Ota, K. Okazaki, Y. Kotani, T. Shimojima, W. Malaeb, S. Watanabe, C.-T. Chen, K. Kihou, C. H. Lee, A. Iyo, H. Eisaki, T. Saito, H. Fukazawa, Y. Kohori, and S. Shin
Phys. Rev. B 89, 081103 (2014).
DOI: 10.1103/PhysRevB.89.081103

[2] Superconductivity in an electron band just above the Fermi level: possible route to BCS-BEC superconductivity
K. Okazaki, Y. Ito, Y. Ota, Y. Kotani, T. Shimojima, T. Kiss, S. Watanabe, C.-T. Chen, S. Niitaka, T. Hanaguri, H. Takagi, A. Chainani, and S. Shin
Sci. Rep. 4, 4109 (2014).
DOI: 10.1038/srep04109

[1] Stripe-Induced High-Temperature Superconductivity in Cuprates
S. Sugai, Y. Takayanagi and J. Nohara, R. Shiozaki, N. Hayamizu, T. Muroi, T. Hosokawa, H. Suzuki, Y. Sone, H. Mabuchi, K. Takenaka, K. Okazaki
J. Supercond. Nov. Magn. 27, 941 (2014).