Ken-Ichiro Imura, Dr.

E-mail: imura[at]hiroshima-u.ac.jp

Research field: condensed-matter physics, theory
Current research topics: topological insulators, semimetals and related systems

Professional activities:

Assistant professor at
- Quantum Matter Program, Graduate School of Advanced Science and Engineering, Hiroshima University
also at
- Center for Emergent-Condensed-Matter Physics
(core research member)

Awards

1. Web of Science, “Highly Cited Article” award for
   "Density of states scaling at the semimetal-to-metal transition in three-dimensional topological insulators"
   Phys. Rev. Lett. 112, 016401 (2014)
   
   by
   Koji Kobayashi, Tomi Ohtsuki, Ken-Ichiro Imura and Igor F. Herbut,
   
   See also, AdSM news and topics.
   
   
2. Journal of the Physical Society of Japan,
   ''2012 Highly Cited Article''
   Award for top 10 articles highly cited in 2012 that were published in 2011
   for
   ''Disorder-Induced Multiple Transition involving Z2 Topological Insulator''
   J. Phys. Soc. Jpn. 80 (2011) 053703
   
   by
   Ai Yamakage, Kentaro Nomura, Ken-Ichiro Imura and Yoshio Kuramoto,
   
   See also, AdSM news and topics.
   
   
3. Papers of Editors' Choice by JPSJ Editorial Board:
   ''2011 Papers of Editors' Choice''
   for
   ''Josephson Current through a Planar Junction of Graphene''
   by
   Yositake Takane and Ken-Ichiro Imura,
   J. Phys. Soc. Jpn. 80 [Letters] 043702 (2011).

Talks, seminars & lectures

1. “Topological insulators and semimetals: surface states, bulk-edge correspondence and disorder effects,” a “featured presentation”
   @ 2016 Xmas Theoretical Physics Symposium, also @ Twitter,
   Victoria University, Wellington, New Zealand, December 5, 2016.
   
   
2. “Comparative study of topological insulators vs. Weyl and Dirac type semimetals:
 bulk-edge correspondence and robustness against disorder,”
   @BEC2016: “Physics of bulk-edge correspondence and its universality: From solid state physics to cold atoms”
   held @YITP Kyoto: Yukawa Institute for Theoretical Physics September 27-30, 2016.
   
   
3. “Comparative study of Dirac/Weyl semimetals and topological/Chern insulators: thin-film point of view,”
   in Conference on Interactions and Topology in Dirac Systems,
   held @ICTP Trieste: Abdus Salam International Centre for Theoretical Physics, August 3-9, 2016.
   
   
4. “From topological insulators to density-of-state scaling”
   @ CMSI,
   ISSP, Kashiwa, March 7, 2016.
   
   
5. "Thin film topological insulators: bulk-edge correspondence, dimensional crossover 
and superlattice generalization,"
   in Physics of bulk-edge correspondence and its universality: from solid state physics to cold atoms,
   Univ. of Tsukuba, Tokyo Campus, Tokyo, September 27-29, 2015.
   
   
6. "Delocalization in disordered topological insulators and related systems,"
   in “Delocalization transitions in disordered systems,”
   Postech, Pohang, Korea, July 24 – August 2, 2015.
   
   
7. “Mesoscopic topological insulator,”
   in New Perspectives in Spintronic and Mesoscopic Physics (NPSMP2015),
   ISSP, Univ. Tokyo, Kashiwa Campus, Japan, June 1-19, 2015.
   
   
8. "Protection of the surface states in topological insulators: Berry phase perspective,"
   in IXth Rencontres du Vietnam, Nanophysics: from fundamentals to applications (the return),
   Quy Nhon, Vietnam, 4-10th August 2013.
   
   
9. “Stability of the topological-insulator surface states: Berry phase perspective,"
   in Japan-Israel Binational Workshop on Quantum Phenomena,
   Okinawa Institute of Science & Technology, Onna-son, Okinawa, March 10 - 13, 2013.
   
   
10. "Spin connection on curved surfaces of the topological insulator",
    in Spin-orbit-driven transverse transport phenomena, Physikzentrum Bad Honnef, 2012.
    
    
11. "Spin-to-surface locking in gapped and gapless topological phases",
    KITP, UC Santa Barbara, 2011: on-line lecture available here

Students in Hiroshima University (2020-21)

- Doctor course


D1: Takahiro Orito


- Master course


M2: Ken Shobe


- Undergraduate course


B4: Keiichi Kuramoto

B4: Ryoto Miyamoto


Past titles of doctor thesis:


2016


Yukinori Yoshimura: "Theoretical study on the surface states of topological insulators"


Past titles of master thesis:


2021


Ken Shobe: "Non-Hermitian Fabry-Perot Resonances in a PT-symmetric system”


2018


Tatsuya Kiriki: "Theoretical study of multipole topological insulators and multipole topological pumping”


2017


Wataru Onishi: "Comparative study of Weyl semimetal and topological/Chern insulators: bulk-edge correspondence in thin-film systems”


2014


Mayuko Okamoto: "Theory of finite-size effects in topological insulator nanostrcures”

Akihiko Matsumoto: "Theory of perfectly conducting channels in topological insulator nanostructures”


2013


Yukinori Yoshimura: "Theory of the spin connection for topological insulator surface states"


Past titles of undergraduate thesis:


2021


Keiichi Kuramoto: “Theoretical study of non-Hermitian scattering problems and resonances”

Ryoto Miyamoto: “Numerical study of the many-body-localization phenomenon”


2020


Kodai Honda: “Spontaneous current in non-Hermitian quantum systems: skin effect, proximity effect and the continuity relation”

Ryota Kito: “Theoretical study of non-Hermitian quantum systems: the complex potential type”


2019


Yuki Yamamoto: “Theoretical study of non-Hermitian topological insulators”


2018


Kensaku Shibata: “Theoretical study on the time evolution of quantum states: case of topological quantum pumping”


2017


Haruka Sone: “Control of electric conduction by Fermi-arc engineering in Weyl semimetals”


2016


Tomoya Matsuoka: “Theory of anisotropic topological insulator: exploring new topological phases”

Tatsuya Kiriki: “Wave-packet dynamics on the surface of strong and weak topological insulators”


2015


Wataru Onishi: “Dimensional crossover of topological properties in nano-ribbon systems”


2014


Shunsuke Iwasaki: “Bulk-boundary correspondence in gapless systems: case of graphene and related systems"


2013


Kai Shinhara: “Bulk-boundary correspondence in gapless systems: case of graphene and related systems"

Koutaro Nakagama: "1D Topological insulator: a model for describing topological insulator nanofilms"


2012


Mayuko Okamoto: “On the surface states of 3D weak and strong topological insulators”

Akihiko Matsumoto: “Theory of topological insulator nanostructures”


2011


Takuya Matsumoto: "Spin-dependent electromagnetic phenomena in topological insulators"


Publications

Google Scholar Citations
Thomson Reuters Researcher ID

Preprint:

1. "Non-Hermitian Fabry-Perot Resonances in a PT-symmetric system"
   Ken Shobe, Keiichi Kuramoto, Ken-Ichiro Imura, Naomichi Hatano, arXiv:2011.02097.

Published:

1. "Theory of nonequilibrium noise in general multiterminal superconducting hybrid devices: Application to multiple Cooper pair resonances"
   R. Jacquet, A. Popoff, K.-I. Imura, J. Rech, T. Jonckheere, L. Raymond, A. Zazunov, and T. Martin, Phys. Rev. B 102, 064510 (2020).
   Preprint: arXiv:2009.00095.
   
   
2. "Generalized Bloch band theory for non-Hermitian bulk–boundary correspondence"
   Ken-Ichiro Imura, Yositake Takane, Progress of Theoretical and Experimental Physics, 2020, 12A103.
   Preprint: arXiv:2004.14772.
   
   
3. "Finite-size effects in cylindrical topological insulators"
   Michele Governale, Bibek Bhandari, Fabio Taddei, Ken-Ichiro Imura, Ulrich Zülicke, New J. Phys. 22, 063042 (2020).
   Preprint: arXiv:2003.01321.
   
   
4. “Generalized bulk-edge correspondence for non-Hermitian topological systems”
   Ken-Ichiro Imura, Yositake Takane, Phys. Rev. B 100, 165430 (2019).
   Preprint: arXiv:1908.09438.
   
   
5. “Short Ballistic Josephson Coupling in Planar Graphene Junctions with Inhomogeneous Carrier Doping”
   Jinho Park, Jae Hyeong Lee, Gil-Ho Lee, Yositake Takane, Ken-Ichiro Imura, Takashi Taniguchi, Kenji Watanabe, and Hu-Jong Lee, Phys. Rev. Lett. 120, 077701 (2018).
   Preprint: arXiv:1712.09740.
   
   
6. “Bulk-edge correspondence in topological transport and pumping”
   Ken-Ichiro Imura, Yukinori Yoshimura, Takahiro Fukui, Yasuhiro Hatsugai, J. Phys.: Conf. Ser. 969 969, 012133 (2018).
   Preprint: arXiv:1706.04493.
   
   
7. “Comparative study of Weyl semimetal and topological/Chern insulators: Thin-film point of view”
   Yukinori Yoshimura, Wataru Onishi, Koji Kobayashi, Tomi Ohtsuki, and Ken-Ichiro Imura, Phys. Rev. B 94, 235414 (2016).
   Preprint: arXiv:1606.02091.
   
   
8. "Dimensional crossover of transport characteristics in topological insulator nanofilms"
   Koji Kobayashi, Ken-Ichiro Imura, Yukinori Yoshimura and Tomi Ohtsuki, Phys. Rev. B 92, 235407 (2015).
   Preprint: arXiv:1409.1707.
   
   
9. "Manipulating quantum channels in weak topological insulator nano-architectures"
   Akihiko Matsumoto, Takashi Arita, Yositake Takane, Yukinori Yoshimura, Ken-Ichiro Imura, Phys. Rev. B 92, 195424 (2015).
   Preprint: arXiv:1412.3897.
   
   
10. "Noninvasive Metallic State"
    Ken-Ichiro Imura and Yositake Takane, JPS Conf. Proc. 4, 013005 (2015).
    
    
11. "Engineering Dirac electrons emergent on the surface of a topological insulator"
    Yukinori Yoshimura, Koji Kobayashi, Tomi Ohtsuki, Ken-Ichiro Imura, Sci. Technol. Adv. Mater. 16, 014403 (2015).
    Preprint: arXiv:1412.4317.
    
    
12. "Characterizing the weak topological properties: Berry phase point of view"
    Yukinori Yoshimura, Ken-Ichiro Imura, Takahiro Fukui and Yasuhiro Hatsugai, Phys. Rev. B 90, 155443 (2014).
    Preprint: arXiv:1405.4842.
    
    
13. "One-dimensional topological insulator: a model for studying finite-size effects in topological insulator thin films"
    Mayuko Okamoto, Yositake Takane and Ken-Ichiro Imura, Phys. Rev. B 89, 125425 (2014).
    Preprint: arXiv:1401.2583.
    
    
14. "Density of states scaling at the semimetal-to-metal transition in three-dimensional topological insulators"
    Koji Kobayashi, Tomi Ohtsuki, Ken-Ichiro Imura and Igor F. Herbut, Phys. Rev. Lett. 112, 016402 (2014).
    “Web of Science, Highly Cited Article.”
    Preprint: arXiv:1308.3953.
    
    
15. "Perfectly conducting channel on the dark surface of weak topological insulators"
    Yukinori Yoshimura, Akihiko Matsumoto, Yositake Takane and Ken-Ichiro Imura, Phys. Rev. B 88, 045408 (2013).
    Preprint: arXiv:1303.0661.
    
    
16. "Symmetry protected weak topological phases in a superlattice"
    T. Fukui, K.-I. Imura and Y. Hatsugai, J. Phys. Soc. Jpn. 82 (2013) 073708 [Letters].
    Preprint: arXiv:1304.6200.
    
    
17. "Unified description of Dirac electrons on a curved surface of topological insulators"
    Yositake Takane and Ken-Ichiro Imura, J. Phys. Soc. Jpn. 82 (2013) 074712.
    Preprint: arXiv:1303.2179.
    
    
18. "Disordered weak and strong topological insulators"
    Koji Kobayashi, Tomi Ohtsuki, Ken-Ichiro Imura, Phys. Rev. Lett., 110, 236803 (2013).
    Preprint: arXiv:1210.4656.
    
    
19. "Criticality of the metal-topological insulator transition driven by disorder"
    Ai Yamakage, Kentaro Nomura, Ken-Ichiro Imura and Yoshio Kuramoto, Phys. Rev. B 87, 205141 (2013).
    Preprint: arXiv:1211.5026.
    
    
20. "Protection of the surface states in topological insulators: Berry phase perspective"
    Ken-Ichiro Imura, Yositake Takane, Phys. Rev. B 87, 205409 (2013).
    Preprint: arXiv:1211.2088.
    
    
21. ''Spin-orbit effects in graphene p-n junction''
    A. Yamakage, K.-I. Imura, J. Cayssol and Y. Kuramoto, AIP Conf. Proc. 1504, pp. 867-870 (2012).
    
    
22. ''Z2-classification of localization properties in graphene''
    Ken-Ichiro Imura, Yoshio Kuramoto and Kentaro Nomura, AIP Conf. Proc. 1504, pp. 871-874 (2012).
    
    
23. ''Finite-size energy gap in weak and strong topological insulators''
    Ken-Ichiro Imura, Mayuko Okamoto, Yukinori Yoshimura, Yositake Takane and Tomi Ohtsuki, Phys. Rev. B 86, 245436 (2012).
    Preprint: arXiv:1208.0654.
    
    
24. ''Spherical topological insulator''
    Ken-Ichiro Imura, Yukinori Yoshimura, Yositake Takane and Takahiro Fukui, Phys. Rev. B 86, 235119 (2012).
    Preprint: arXiv:1205.4878.
    
    
25. Topological insulator "nanotubes"
    Ken-Ichiro Imura, Yositake Takane and Akihiro Tanaka, J. Phys.: Conf. Ser. 400, 042021 (2012).
    
    
26. "Stationary Josephson effect in ballistic graphene junctions: effects of inhomogeneous carrier density"
    Ken-Ichiro Imura and Yositake Takane, J. Phys.: Conf. Ser. 400, 042057 (2012).
    
    
27. "Z2 Topological Anderson Insulator"
    Ai Yamakage, Kentaro Nomura, Ken-Ichiro Imura and Yoshio Kuramoto, J. Phys.: Conf. Ser. 400, 042070 (2012).
    
    
28. "Quasiclassical Theory of the Josephson Effect in Ballistic Graphene Junctions"
    Yositake Takane and Ken-Ichiro Imura, J. Phys. Soc. Jpn. 81 (2012) 094707.
    Preprint: arXiv:1208.3264.
    
    
29. "Dirac electrons on a sharply edged surface of topological insulators"
    Yositake Takane and Ken-Ichiro Imura, J. Phys. Soc. Jpn. 81 (2012) 093705 [Letters].
    Preprint: arXiv:1208.1571.
    
    
30. ''Perfectly conducting channel and its robustness in disordered carbon nanostructures''
    Yuki Ashitani, Ken-Ichiro Imura and Yositake Takane, Int. J. Mod. Phys. 11, 157-162 (2012).
    Preprint: arXiv:1206.6234.
    
    
31. ''Majorana bound state of a Bogoliubov-de Gennes-Dirac Hamiltonian in arbitrary dimensions''
    Ken-Ichiro Imura, Takahiro Fukui and Takanori Fujiwara, Nucl. Phys. B 854, 306-320 (2012).
    Preprint: arXiv:1107.5629.
    
    
32. ''Spin Berry phase in the Fermi arc states''
    Ken-Ichiro Imura and Yositake Takane, Phys. Rev. B 84, 245415 (2011)
    Preprint: arXiv:1109.3243.
    
    
33. ''Spin Berry phase in anisotropic topological insulators''
    Ken-Ichiro Imura, Yositake Takane and Akihiro Tanaka, Phys. Rev. B 84, 195406 (2011)
    Preprint: arXiv:1108.0522
    
    
34. ''Weak topological insulator with protected gapless helical states''
    Ken-Ichiro Imura, Yositake Takane and Akihiro Tanaka, Phys. Rev. B 84, 035443 (2011)
    Preprint: arXiv:1103.1430.
    
    
35. ''Disorder-Induced Multiple Transition involving Z2 Topological Insulator''
    Ai Yamakage, Kentaro Nomura, Ken-Ichiro Imura and Yoshio Kuramoto, J. Phys. Soc. Jpn. 80 (2011) 053703 [Letters].
    “JPSJ 2012 Highly Cited Article.”
    Preprint: arXiv:1011.5576.
    
    
36. ''Josephson Current through a Planar Junction of Graphene''
    Yositake Takane and Ken-Ichiro Imura, J. Phys. Soc. Jpn. 80 [Letters] 043702 (2011).
    “JPSJ Paper of Editor's Choice.”
    Preprint: arXiv:1105.2600.
    
    
37. ''Interfacial charge and spin transport in Z2 topological insulators''
    A. Yamakage, K.-I. Imura, J. Cayssol and Y. Kuramoto, Phys. Rev. B 83, 125401 (2011).
    Preprint: arXiv:1009.2842.
    
    
38. ''Flat edge modes of graphene and of Z2 topological insulator''
    K.-I. Imura, Shijun Mao, A. Yamakage and Y. Kuramoto, Nanoscale Res. Lett. 6, 358 (2011).
    
    
39. ''Analytic Theory of Edge Modes in Topological Insulators''
    Shijun Mao, Yoshio Kuramoto, Ken-Ichiro Imura and Ai Yamakage, J. Phys. Soc. Jpn 79 (2010) 124709.
    Preprint: arXiv:1008.0481.
    
    
40. ''Zigzag edge modes in a Z2 topological insulator: Reentrance and completely flat spectrum''
    Ken-Ichiro Imura, Ai Yamakage, Shijun Mao, Akira Hotta and Yoshio Kuramoto, Phys. Rev. B 82, 085118 (2010).
    Preprint: arXiv:1004.5019.
    
    
41. ''Weak localization properties of graphene with intrinsic and Rashba spin-orbit couplings''
    K.-I. Imura, Y. Kuramoto and Ken Nomura, Physics Procedia 3, 1249-1254 (2010).
    
    
42. ''Klein tunneling in graphene under substrate electric field''
    A. Yamakage, K.-I. Imura, J. Cayssol and Y. Kuramoto, Physics Procedia 3, 1243-1248 (2010).
    
    
43. ''Anti-localization of graphene under the substrate electric field''
    K.-I. Imura, Y. Kuramoto and Ken Nomura, Europhys. Lett. 89, 17009 (2010).
    Preprint: arXiv:0904.1676.
    
    
44. ''Spin-orbit effects in a graphene bipolar pn junction''
    A. Yamakage, K.-I. Imura, J. Cayssol and Y. Kuramoto, Europhys. Lett. 87, 47005 (2009).
    Preprint: arXiv:0906.0775.
    
    
45. ''Weak localization properties of doped Z2 topological insulator''
    Ken-Ichiro Imura, Yoshio Kuramoto and Kentaro Nomura, Phys. Rev. B 80, 085119 (2009).
    Preprint: arXiv:0907.5051.
    
    
46. ''Colossal spin fluctuations in a molecular quantum dot magnet with ferromagnetic electrodes''
    T. Jonckheere, K.-I. Imura and Th. Martin, Phys. Rev. B 78, 045316 (2008).
    Preprint: arXiv:0803.3058.
    
    
47. ''Quantum Hall effect in bilayer and multilayer graphene with finite Fermi energy''
    M. Nakamura, L. Hirasawa and K.-I. Imura, Phys. Rev. B 78, 033403 (2008).
    Preprint: arXiv:0804.4599.
    
    
48. ''Numerical study of transport through a single impurity in a spinful Tomonaga–Luttinger liquid''
    Y. Hamamoto, K.-I. Imura and T. Kato, Phys. Rev. B 77, 165402 (2008).
    Preprint: arXiv:0710.3474.
    
    
49. ''Full counting statistics for molecular spintronics''
    K.-I. Imura, Y. Utsumi and Th. Martin, Physica E 3, 375-378 (2007).
    
    
50. ''Full counting statistics for transport through a molecular quantum dot magnet''
    K.-I. Imura, Y. Utsumi and Th. Martin, Phys. Rev. B 75, 205341 (2007).
    Preprint: arXiv:cond-mat/0612052.
    
    
51. "Characterization of two-dimensional fermionic insulating states"
    Ryuichi Shindou, Ken-Ichiro Imura and Masao Ogata, Phys. Rev. B 74, 245107 (2006).
    Preprint: arXiv:0706.4258.
    
    
52. "Topological currents in ferromagnets and related systems: from the viewpoint of wave-packet dynamics"
    Ryuichi Shindou and Ken-Ichiro Imura, phys. stat. sol. (b) 243, pp. 174–178 (2006).
    
    
53. "Electron-electron interactions in a one-dimensional quantum-wire spin filter"
    P. Devillard, A. Crépieux, K.-I. Imura and Th. Martin, Phys. Rev. B 72, R041309 (2005).
    Preprint: arXiv:cond-mat/0501145.
    
    
54. "Noncommutative geometry and non-Abelian Berry phase in the wave-packet dynamics of Bloch electrons"
    Ryuichi Shindou and Ken-Ichiro Imura, Nucl. Phys. B 720, pp. 399-435 (2005).
    Preprint: arXiv:cond-mat/0411105.
    

On arXiv:

1. "(De)confinement of supercurrent in Z_2 Topological Insulators"
   Jun Goryo, Nobuki Maeda, Ken-Ichiro Imura, arXiv:0905.2296.