Thermoelectric study of quantum criticality in heavy-fermion metals

2012 Fiscal Year Final Research Report

• Project/Area Number: 23740263
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: MACHIDA Yo 東京工業大学, 大学院・理工学研究科, 助教 (40514740)
• Project Period (FY): 2011 – 2012
• Keywords: 強相関系

Research Abstract

Quantum critical phenomena of the heavy-fermion materials have been studied by the low-temperature thermoelectric coefficient measurements. As a result, distinct nature of quantum criticality between two representative Yb-based quantum critical materials β-YbAlB4 and YbRh 2 Si2 has been revealed by contrasting behaviors of the Seebeck coefficient near their quantum critical points (QCP). Moreover, a satisfactory of the Wiedemann-Franz law has been verified in YbRh 2 Si2 at the QCP. These results place strong constraint on models for the quantum criticality of these materials.

Research Products

• [Journal Article] Magnetic Field Driven Electronic Singularities through Metamagnetic Phenomena: Case of the Heavy Fermion Antiferromagnet Ce(Ru_0.92Rh_0.08)_2 Si_2 (2013)
  • Author(s): Y. Mach ida, K. Izawa, D. Aoki, G. Knebel, A.Pourret, and J. Flouquet
  • Journal Title: Journal of the Physical Society of Japan Volume: 82 Pages: 054704
  • Peer Reviewed
• [Journal Article] Thermoelectric Response Near a Quantum Critical Point of β-YbAlB_4 and YbRh_2Si_2 : A Comparative Study (2012)
  • Author(s): Y. Machida, K. Tomokuni, C. Ogura, K.Izawa, K. Kuga, S. Nakatsuji, G. Lapertot, G. Knebel, J.-P. Brison, and J. Flouquet
  • Journal Title: Physical ReviewLetters Volume: 109 Pages: 156405
  • Peer Reviewed
• [Journal Article] Twofold Spontaneous Symmetry Breaking in the Heavy-Fermion Superconductor UPt_3 (2012)
  • Author(s): Y. Machida, A. Itoh, Y. So, K. Izawa, Y.Haga, E. Yamamoto, N. Kimura, Y. Onuki, Y. Tsutsumi, and K. Machida
  • Journal Title: Physical Review Letters Volume: 108 Pages: 157002
  • Peer Reviewed
• [Journal Article] Anisotropic Hysteretic Hall Effect and Magnetic Control of Chiral Domains in the Chiral Spin States of Pr_2Ir_2O_7 (2011)
  • Author(s): L. Balicas, S. Nakatsuji, Y. Machida, and S.Onoda
  • Journal Title: Physical Review Letters Volume: 106 Pages: 217204
  • Peer Reviewed
• [Journal Article] Verification of the Wiedemann-Franz Law in YbRh_2Si_2 At a Quantum Critical Point
  • Author(s): Y. Machida, K. Tomokuni, K. Izawa, G. Lapertot, G. Knebel, J.-P. Brison, and J. Flouquet
  • Journal Title: Physical Review Letters誌 Volume: (掲載決定)
  • Peer Reviewed
• [Presentation] 多重超伝導相をもつUPt3の極低温熱ホール伝導率 (2013)
  • Author(s): 町田洋,伊藤淳史,井澤公一,芳賀芳範,山本悦嗣,木村憲彰,大貫惇睦
  • Organizer: 日本物理学会年次大会
  • Place of Presentation: 広島大学
  • Year and Date: 2013-03-29
• [Presentation] 重い電子系Ce(Ru_1-xRh_x)_2 Si_2の極低温熱電 (2012)
  • Author(s): 町田洋,井澤公一,青木大,A. Pourret, J. Flouquet , K. Behnia
  • Organizer: 日本物理学会秋季大会
  • Place of Presentation: 横浜国立大学
  • Year and Date: 2012-09-20
• [Presentation] Thermoelectric study of the metamagnetic behavior in YbCo2 Zn 20 (2012)
  • Author(s): Y. Machida, T. Ikeura, K. Izawa, S.Yoshiuchi, F. Honda, R. Settai, and Y. Onuki
  • Organizer: ICM 2012
  • Place of Presentation: Busan, Korea
  • Year and Date: 2012-07-09
• [Presentation] 重い電子系化合物YbCo_2Zn_20の低温熱電係数 (2012)
  • Author(s): 町田洋,池浦徹,井澤公一,吉内伸吾,本多史憲,摂待力生,大貫惇睦
  • Organizer: 日本物理学会年次大会
  • Place of Presentation: 関西学院大学
  • Year and Date: 2012-03-27
• [Presentation] Comparative Study on Quantum Criticality of β-YbAlB_4 and YbRh_2Si_2 via Thermal Transport Measurements (2011)
  • Author(s): Y. Machida, K. Tomokuni, C. Ogura, K.Izawa, K. Kuga, S. Nakatsuji, G. Lapertot, G. Knebel, J.-P. Brison, and J. Flouquet
  • Organizer: SCES 2011
  • Place of Presentation: Cambridge, UK
  • Year and Date: 2011-09-02