Dr. Shigeru Kasahara　To Japanese page

 

Superconducting Materials Center,

National Institute for Materials Science (NIMS)

1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan

Tel: +81-29-859-2316(direct) Fax: +81-29-859-2301

e-mail: KASAHARA.Shigeru“at”nims.go.jp   (please replace “at” by @)

http://www.nims.go.jp/filmcrystal/kasahara_e.htm

 

Date & Place of Birth: 23rd, Dec. 1975, Tokyo, Japan

 

 

Last update, 1st Apr. 2007.

Academic Positions    

 

Apr. 2005-present

NIMS Postdoctoral Research Assoc., Superconducting Materials Center,

National Institute for Materials Science (Group Leader: Dr. K. Hirata

Tsukuba, Ibaraki, Japan

 

Apr. 2003-May 2005

Postdoctoral Research Assoc., Department of Applied Physics, and also in Quantum-Phase Electronics Center,

The University of Tokyo (Group Leader: Prof. T. Tamegai)

Bunkyo-ku, Tokyo, Japan

 

 

 

Academic Degrees

 

Ph. D. in Physics, Toho University, Japan 2003.

Dissertation: “Studies on Vortex Dynamics in Layered Organic Superconductors --- Complex Susceptibility and Electrical Resistance ---”

Advisor: Prof. Koji Kajita (JPSJ, Ex-Chief Editor)

 

Master in Physics, Toho University, Japan 2000.

Thesis: “Vortex behavior in an Organic Superconductor k-(BEDT-TTF)2Cu(NCS)2”

Advisor: Prof. Koji Kajita

 

Bachelor in Physics, Toho University, Japan 1998.

 

 

 

Other Academic Positions

 

Teaching assistant, 2000-2003

Department of Physics, Toho University

-Assisted lectures for graduate students: Statistical-Mechanics

 

Teaching assistant, 1998-2000

Department of Physics, Toho University

-Assisted experiments for graduate students

 

 

 

Research Interests

 

Mostly interested in the exotic superconductivity with unconventional pairing mechanism. Recently focused on the superconducting state with broken time-reversal symmetry realized in a filled-skutterudites PrOs4Sb12, by applying local magnetization measurements and magneto-optical imaging technique, thermodynamic measurements, etc. Also vortex state in high-Tc and layered organic superconductors, and transport measurements including nano-scale materials.

 

 

 

Skills

 

Languages

l         Japanese in Native, English in Fluent.

 

Experimental Skills

l         Local magnetization and local ac permeability measurements using micro Hall-probe.

l         Visualization of local field distribution using magneto-optical technique.

l         Micro and nano-fabrications by photo and electron beam lithography.

l         Transport measurements including nano-scale materials.

l         Ac susceptibility measurements by various techniques (rf-measurements by self-inductance technique, lf-measurements by mutual inductance technique, and 2-phase rf-measurements by balanced resonance technique).

l         Heat capacity measurements by thermal relaxation method.

l         High quality single crystal synthesis by traveling solvent floating zone (TSFZ) method.

l         Electro-chemical synthesis of organic charge transfer salts.

l         Experimental software writing by Visual Basic and other languages.

l         Other commercial instruments like SQUID magnetometer etc.

 

 

Computational Skills

l         Mainly using Windows OS, but also versed in UNIX System, especially in NEXTSTEP, and Mac OS X.

l         Making experimental programs by Visual BASIC language.

l         Also can make applications by NI-LabVIEW, Agilent-VEE, and classic N88BASIC etc.

l         Composing papers mainly by LaTeX, and optionally MS-Word etc.

 

 

 

Research Activities

 

Supported by a Grant-in-Aid for Scientific Research Young Scientists (B), 18740214; “Studies on domain structure in superconductors with broken time-reversal symmetry”, from the Ministry of Education, Culture, Sports, Science and Technology, Japan.

 

JSPS (Japan Society for the Promotion of Science) Core-to-Core Program, “Nano-science and Engineering in Superconductivity”, collaborator from Japanese side (2003-2005).

 

 

16 articles published in refereed journals, 3 accepted articles in press, and 3 articles under review. 2 articles in unrefereed journals.

12 presentations in the international conferences as a first author.

35 presentations in the domestic meetings or workshops, including 2 invited talks.

 

 

List of Publications

 

[1] “Local magnetization anomaly in PrOs4Sb12　with broken time-reversal symmetry; evidence for superconducting state with multi-domains”,

S. Kasahara, K. Hirata, T. Tamegai, H. Sugawara, D. Kikuchi, H. Sato, in preparation.

 

[2] “Elastic anomaly of vortices in layered organic superconductors studied by complex susceptibility with large modulations”,

S. Kasahara, Y. Nishio, K. Kajita, K. Hirata, T. Tamegai, to be submitted to J. Phys. Soc. Jpn.

 

[3] “Low temperature specific heat of ternary germanide superconductor La3Pd4Ge4 with U3Ni4Si4-type structure”,

S. Kasahara, H. Fujii, T. Mochiku, H. Takeya and K. Hirata, submitted to Phys. Rev. B (2007). arXiv:0708.0129v1 [cond-mat. supr-con].

 

[4] “Superconductivity in the ternary intermetallics of La3Ni4X4 (X=Si and Ge)”,

H. Fujii and S. Kasahara, submitted to Phys. Rev. B (2007).　

 

[5] “Specific heat of novel ternary superconductors La3Ni4X4 (X=Si AND Ge)”,

S. Kasahara, H. Fujii, T. Mochiku, H. Takeya and K. Hirata, submitted to Physica C (2007).

 

[6]“Superconducting double transition in PrOs4Sb12 probed by local magnetization measurements and magneto-optical imaging”,

Shigeru Kasahara, Kazuto Hirata, Tsuyoshi Tamegai, Hitoshi Sugawara, Daisuke Kikuchi, Hiduyuki Sato,  to be published in J. Phys. Soc. Jpn. Suppl. (2007).

 

[7]“Low temperature specific heat of ternary germanide superconductor La3Pd4Ge4”,

S. Kasahara, H. Fujii, T. Mochiku, H. Takeya and K. Hirata, to be published in Physica B (2007).

doi:10.1016/j.physb.2007.10.347

 

[8] “Specific heat of Li2(Pd1-xPtx)3B under magnetic field”,

H. Takeya, S. Kasahara, M.El.Massalami, K. Hirata and K. Togano, to be published in Physica B (2007). 

doi:10.1016/j.physb.2007.10.249

 

[9] “Specific heat of the spin-orbit interaction in noncentrosymmetric Li2(Pd1-xPtx)3B”,

H. Takeya, M. ElMassalami, S. Kasahara and K. Hirata, Phys. Rev. B 76, 104506 (2007).

 

[10] “Physical Properties of Li2Pd3B and Li2Pt3B Superconductors”,

Hiroyuki Takeya, Shigeru Kasahara, Mohammed El Massalami, Takashi Mochiku, Kazuto Hirata, and Kazumasa Togano, Materials Science Forum, 561-565, 2079 (2007).

 

[11] “Specific heat of lithium ternary borides under magnetic field”,

H. Takeya, S. Kasahara, M.E. Massalami, K. Hirata, K. Togano, Physica C 463-465, 111-114 (2007).

 

[12] “Specific heat of the spin-orbit interaction in noncentrosymmetric Li2(Pd1-xPtx)3B”,

H. Takeya, M. ElMassalami, S. Kasahara and K. Hirata, Phys. Rev. B 76, 104506 (2007).

 

[13] “Positive local magnetization in the superconducting state of PrOs4Sb12”,

Shigeru Kasahara, Kazuto Hirata, Tsuyoshi Tamegai, Hitoshi Sugawara, Daisuke Kikuchi and Hideyuki Sato, Physica C 463-465, 71-75 (2007).

 

[14] “Double transition in PrOs4Sb12 probed by local magnetization measurements using Hall probe array”,

S. Kasahara, K. Hirata, T. Tamegai, H. Sugawara, D. Kikuchi, H. Sato, Physica C 460-462, 696-697 (2007).

 

[15] “Pressure effect and superconducting properties of lithium ternary borides”,

Hiroyuki Takeya, Mohammed El Massalami, Kazuto Hirata, Takashi Mochiku, Shigeru Kasahara, Kazumasa Togano, Physica C 460-462, 89-90 (2007).

 

[16] “Local field measurements in PrOs4Sb12 with broken time-reversal symmetry”,

Shigeru Kasahara, Tsuyoshi Tamegai, Hitoshi Sugawara, Hideyuki Sato, AIP Conf. Proc. 850, 651-652 (2006).

 

[17] “Peculiar superconductivity in PrOs4Sb12 probed by local magnetization”,

Shigeru Kasahara, Tsuyoshi Tamegai, Hitoshi Sugawara, Hideyuki Sato, Physica C 426-431, 381-385 (2005).

 

[18] “Local magnetization anomalies and inhomogeneous penetration of vortices in Bi2Sr2CaCu2O8+y”,

S. Kasahara, Y. Tokunaga, N. Kameda, M. Tokunaga, and T. Tamegai, Phys. Rev. B 71, 224505 (2005).

 

[19] “Vortex States in Highly Anisotropic Superconductors”,

T. Tamegai, M. Tokunaga, S. Kasahara, M. Matsui, and H. Aoki,　Proceedings of the Ninth Asia Pacific Physics Conference (9th APPC), (2005).

 

[20] “Comparative study of anisotropic superconductivity in CaAlSi and CaGaSi”,

T. Tamegai, K. Uozato, S. Kasahara, T. Nakagawa, and M. Tokunaga, Physica C 426-431, 208 (2005).

 

[21] “Multiple magnetization peaks and inhomogeneous vortex penetration in the crossing-lattices state of Bi2Sr2CaCu2O8+y”,

S. Kasahara, Y. Tokunaga, N. Kameda, M. Tokunaga, and T. Tamegai, Proceedings of the Joint Meeting of FIMS/ITS-NS/CTC/PLASMA, II-134, (2004).

 

[22] “Doping dependence of crossing vortex lattice in Bi2Sr2CaCu2O8+y”,

Shigeru Kasahara, Naoto Kameda, Masashi Tokunaga and Tsuyoshi Tamegai, Physica C 412-414, 440-443 (2004).

 

[23] “Pinning anomalies in organic layered superconductor k-(BEDT-TTF)2X (X =Cu(NCS)2, Cu[N(CN)2]Br)”,

Shigeru Kasahara, Fumitoshi Tateishi, Hiroyuki Caneko, Takashi Hara, Yutaka Nishio and Koji Kajita, Physica C 388-389, 607-608 (2003).

 

[24] “Resistance oscillation and dynamical instabilities of vortices in k-(BEDT-TTF)2Cu(NCS)2”,

Shigeru Kasahara, Fumitoshi Tateishi, Hiroyuki Caneko, Takashi Hara, Yutaka Nishio and Koji Kajita, Synthetic Metals 137, 1283 (2003).

 

[25] “Dynamical behavior of vortices introduced into a layered superconductor k-(BEDT-TTF)2Cu(NCS)2”,

Shigeru Kasahara, Yutaka Nishio and Koji Kajita, Synthetic Metals 120, 937 (2001).

 

[26] “Vortex motion in an organic superconductor k-(BEDT-TTF)2Cu(NCS)2”,

T. Ichikawa S. Kasahara, M. Tamura, Y. Nishio and K. Kajita, Synthetic Metals 103, 1822 (1999).

 

 

 

International Conference Presentations (List only for the First author)

 

 

[1] “Specific heat of novel ternary superconductors La3Ni4X4 (X=Si and Ge) ”,

S. Kasahara, H. Fujii, T. Mochiku, H. Takeya and K. Hirata

Nov. 5-7, 2007, The 20th International Symposium on Superconductivity (ISS2007), Tsukuba, Japan.

 

[2] “Double transition in PrOs4Sb12 and the superconductivity with broken time-reversal symmetry probed by local magnetization measurements using micro-Hall probe array”,　

S. Kasahara, K. Hirata, T. Tamegai, H. Sugawara, D. Kikuchi, H. Sato,

Sep. 26-30, 2007, International Conference on "New Quantum Phenomena in Skutterudite and Related Systems", Kobe, Japan.

 

[3] “Low temperature specific heat of ternary germanide superconductor La3Pd4Ge4”,

S. Kasahara, H. Fujii, T. Mochiku, H. Takeya and K. Hirata,

May 13-18, 2007, The International Conference on Strongly Correlated Electron Systems (SCES2007), Houston, USA.

 

[4] “Positive local magnetization in the superconducting state of PrOs4Sb12”,

S. Kasahara, K. Hirata, T. Tamegai, H. Sugawara, D. Kikuchi, and H. Sato,

Oct. 2006, The 19th International Symposium on Superconductivity (ISS2006), Nagoya, Japan.

 

[5] “Double transition in PrOs4Sb12 probed by local magnetization measurements using Hall probe array”,

S. Kasahara, K. Hirata, T. Tamegai, H. Sugawara, D. Kikuchi, and H. Sato,

Jul. 2006, The 8th International Conference on Materials and Mechanisms of Superconductivity High Temperature Superconductors (M2S-HTSC), Dresden, Germany.

 

[6] “Local field measurements in PrOs4Sb12 with broken time-reversal symmetry”,

Shigeru Kasahara, Tsuyoshi Tamegai, Hitoshi Sugawara, and Hideyuki Sato,

Aug. 2005, The 24th International Conference on Low Temperature Physics, Orlando, Florida, USA.

 

[7] “Peculiar superconductivity in PrOs4Sb12 probed by local magnetization”,

Shigeru Kasahara, Tsuyoshi Tamegai, Hitoshi Sugawara, Hideyuki Sato,

Nov. 2004, The 17th International Symposium on Superconductivity (ISS2004), Nigata, Japan.

 

[8] “Multiple magnetization peaks and inhomogeneous vortex penetration in the crossing-lattices state of Bi2Sr2CaCu2O8+y”,

S. Kasahara, Y. Tokunaga, N. Kameda, M. Tokunaga, and T. Tamegai,

Oct. 2004, Joint Meeting of FIMS/ITS-NS/CTC/PLASMA-2004, Tsukuba, Japan.

 

[9] “Doping dependence of crossing vortex lattice in Bi2Sr2CaCu2O8+y”,

Shigeru Kasahara, Naoto Kameda, Masashi Tokunaga and Tsuyoshi Tamegai,

Nov.  2003, The 16th International Symposium on Superconductivity (ISS2003), Tsukuba, Japan, 2003.

 

[10] “Pinning anomalies in organic layered superconductor k-(BEDT-TTF)2X {X =Cu(NCS)2, Cu[N(CN)2]Br}”,

Shigeru Kasahara, Fumitoshi Tateishi, Hiroyuki Caneko, Takashi Hara, Yutaka Nishio and Koji Kajita,

Aug, 2002. The 23rd International Conference on Low Temperature Physics (LT23), Hiroshima, Japan.　

 

[11] “Resistance oscillation and dynamical instabilities of vortices in k-(BEDT-TTF)2Cu(NCS)2”,

Shigeru Kasahara, Fumitoshi Tateishi, Hiroyuki Caneko, Takashi Hara, Yutaka Nishio and Koji Kajita,

Jun. 2002, International Conference on Science and Technology of Synthetic Metals (ICSM2002), Shanghai, China.

 

[12] “Dynamical behavior of vortices introduced into a layered superconductor k-(BEDT-TTF)2Cu(NCS)2”,

Shigeru Kasahara, Yutaka Nishio and Koji Kajita,

Jul. 2000, International Conference on Science and Technology of Synthetic Metals (ICSM2000), Gastein, Autsria.

 

 

 

References

 

Dr. Kazuto Hirata

Superconducting Materials Center,

National Institute for Materials Science (NIMS).

 

Prof. Tsuyoshi Tamegai

Department of Applied Physics, The University of Tokyo.

 

Prof. Koji Kajita

Department of Physics, Toho university.