Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Bi
Se
Wang, J.*; Ran, K.*; Li, S.*; Ma, Z.*; Bao, S.*; Cai, Z.*; Zhang, Y.*; 中島 健次; 河村 聖子; 
erm
k, P.*; et al.
Nature Communications (Internet), 10, p.2802_1 - 2802_6, 2019/06
被引用回数：18 パーセンタイル：79.92(Multidisciplinary Sciences)Superconductivity mediated by phonons is typically conventional, exhibiting a momentum-independent 
-wave pairing function, due to the isotropic interactions between electrons and phonons along different crystalline directions. Here, by performing inelastic neutron scattering measurements on a superconducting single crystal of SrBiSe, a prime candidate for realizing topological superconductivity by doping the topo-logical insulator BiSe, we found that there exist singular phonons, with the linewidths of the acoustic phonons increasing substantially at long wavelengths, but only for those along the [001] direction. This observation indicates a large and singular electron-phonon coupling at small momenta, which we propose to give rise to the exotic 
-wave nematic superconducting pairing in the MxBiSe (M = Cu, Sr, Nb) superconductor family. Therefore, we show that these superconductors may be the first examples where electron-phonon interaction can induce more exotic superconducting pairing than the -wave.
Si金子 耕士; Stockert, O.*; Skoulatos, M.*; Schneidewind, A.*; 竹内 徹也*; 松田 達磨; 芳賀 芳範; 摂待 力生*; 大貫 惇睦; 目時 直人
Journal of the Physical Society of Japan, 81(Suppl.B), p.SB006_1 - SB006_7, 2012/12
被引用回数：2 パーセンタイル：19.67(Physics, Multidisciplinary)The discovery of heavy-fermion superconductivity in non-centrosymmetric compound CePt
Si, and subsequent findings of Ce
(T: transition metal, X: Si, Ge) bring a new essence in the condensed matter physics, since a novel type of superconducting properties is expected to come out. In CePtSi, the compound shows an antiferromagnetic (AFM) order at 
=2.2 K and enters into a heavy-fermion superconducting state below 
0.5 K. Through neutron scattering experiments under external magnetic field, we identified anomalous field response in CePtSi in the AFM state; AFM intensity showed enormous enhancement with increasing an applied field. The intensity kept increasing up to 7 T with the kink at around the additional phase boundary. These features suggest that the magnetic order in CePtSi is not a simple AFM one, and imply that large fraction of magnetic response could be still missing in this compound.
Si金子 耕士; Stockert, O.*; Arndt, J.*; Borth, R.*; Skoulatos, M.*; Habicht, K.*; Kiefer, K.*; Schneidewind, A.*; Etzdorf, D.*; 竹内 徹也*; et al.
no journal, ,
The heavy-fermion superconductivity in CePtSi with a non-centrosymmetric structure attracts a lot of attention since novel superconducting properties are expected under this symmetry. Another characteristics of the superconductivity in CePtSi is its coexistence with long-range antiferromagnetic order. Therefore detailed antiferromagnetic properties and its interplay with superconductivity are of strong interest to investigate. The magnetic structure of CePtSi is represented by 
=(0,0,1/2). We have observed that the 0 0 1/2 antiferromagnetic reflection exhibits a peculiar response to an external magnetic field; its intensity increases with magnetic fields. These results imply unusual antiferromagnetism in CePtSi.
Si金子 耕士; Stockert, O.*; Arndt, J.*; Borth, R.*; Skoulatos, M.*; Habicht, K.*; Kiefer, K.*; Schneidewind, A.*; Etzdorf, D.*; 竹内 徹也*; et al.
no journal, ,
The heavy-fermion superconductivity in CePtSi with a non-centrosymmetric structure attracts a lot of attention since novel superconducting properties are expected under this symmetry. Another characteristics of the superconductivity in CePtSi is its coexistence with long-range antiferromagnetic order. Therefore detailed antiferromagnetic properties and its interplay with superconductivity are of strong interest to investigate. The magnetic structure of CePtSi is represented by 
=(0,0,1/2). We have observed that the 0 0 1/2 antiferromagnetic reflection exhibits a peculiar response to an external magnetic field; its intensity increases with magnetic fields. These results imply unusual antiferromagnetism in CePtSi.
Si金子 耕士; Stockert, O.*; Skoulatos, M.*; Schneidewind, A.*; 竹内 徹也*; 松田 達磨; 芳賀 芳範; 摂待 力生*; 大貫 惇睦; 目時 直人
no journal, ,
CePtSi without inversion symmetry exhibits an antiferromagnetic (AFM) order at 2.2 K and enters into a heavy-fermion superconducting state below 0.5 K. Additional anomalies inside the AFM state were found under external magnetic fields in the vicinity of the upper critical field of the superconducting state. Our neutron scattering experiments under magnetic fields revealed that the application of the magnetic fields leads to an enormous enhancement in the AFM peak intensity in CePtSi, opposite to what is observed in usual antiferromagnets. We have clarified that the reported anomaly under the magnetic fields corresponds to inflection points in the field variation of the AFM intensity. The observed huge increase in AFM intensity corresponds to an increase of the ordered moment under the magnetic fields. These results imply an existence of a missing magnetic response in the ground state, which might be related to the formation of the superconducting state in CePtSi.
Si金子 耕士; Stockert, O.*; Skoulatos, M.*; Schneidewind, A.*; 竹内 徹也*; 松田 達磨; 芳賀 芳範; 摂待 力生*; 大貫 惇睦; 目時 直人
no journal, ,
The discovery of heavy-fermion superconductivity in non-centrosymmetric compound CePtSi brings a new essence in the field of condensed matter physics, since a novel type of superconducting properties are expected to emerge. CePtSi shows an antiferromagnetic (AFM) order at 
=2.2 K and enters into a heavy-fermion superconducting state below 
0.5 K. We identified anomalous external magnetic field response in CePtSi by neutron scattering experiments in the AFM state. An observed huge increase in AFM intensity corresponds to an increase of the staggered moment under uniform field, opposite of what is observed in ordinary antiferromagnets. These features suggest that the magnetic order in CePtSi is not a simple AFM one, and imply that large fraction of magnetic response could be still missing in this compound.
