フルテキストURL PhysRevB_97_134507.pdf
著者 Tanaka, Kenta K.| Ichioka, Masanori| Onari, Seiichiro|
抄録 Local NMR relaxation rates in the vortex state of chiral and helical p-wave superconductors are investigated by the quasiclassical Eilenberger theory. We calculate the spatial and resonance frequency dependences of the local NMR spin-lattice relaxation rate T-1(-1) and spin-spin relaxation rate T-2(-1). Depending on the relation between the NMR relaxation direction and the d-vector symmetry, the local T-1(-1) and T-2(-1) in the vortex core region show different behaviors. When the NMR relaxation direction is parallel to the d-vector component, the local NMR relaxation rate is anomalously suppressed by the negative coherence effect due to the spin dependence of the odd- frequency s-wave spin-triplet Cooper pairs. The difference between the local T-1(-1) and T-2(-1) in the site-selective NMR measurement is expected to be a method to examine the d-vector symmetry of candidate materials for spin-triplet superconductors.
備考 This is an article published by American Physical Society
発行日 2018-04-10
出版物タイトル Physical Review B
97巻
出版者 American Physical Society
開始ページ 134507
ISSN 2469-9950
NCID AA11187113
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
論文のバージョン publisher
DOI 10.1103/PhysRevB.97.134507
Web of Sience KeyUT 000429524500002
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.97.134507
フルテキストURL PhysRevB_96_024414.pdf
著者 Inoue, Masashi| Ichioka, Masanori| Adachi, Hiroto|
抄録 Spin pumping refers to the microwave-driven spin current injection from a ferromagnet into the adjacent target material. We theoretically investigate the spin pumping into superconductors by fully taking account of impurity spin-orbit scattering that is indispensable to describe diffusive spin transport with finite spin diffusion length. We calculate temperature dependence of the spin pumping signal and show that a pronounced coherence peak appears immediately below the superconducting transition temperature Tc, which survives even in the presence of the spin-orbit scattering. The phenomenon provides us with a new way of studying the dynamic spin susceptibility in a superconducting thin film. This is contrasted with the nuclear magnetic resonance technique used to study a bulk superconductor.
備考 This is an article published by American Physical Society
発行日 2017-07
出版物タイトル Physical Review B
96巻
2号
出版者 American Physical Society
開始ページ 024414
ISSN 2469-9950
NCID AA11187113
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
著作権者 American Physical Society
論文のバージョン publisher
DOI 10.1103/PhysRevB.96.024414
Web of Sience KeyUT 000405363500003
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.96.024414
フルテキストURL PhysRevB_93_094507.pdf
著者 Tanaka, Kenta K.| Ichioka, Masanori| Onari, Seiichiro|
抄録 In order to identify the pairing symmetry with chirality, we study site-selective NMR in chiral p-wave superconductors. We calculate local nuclear relaxation rate T-1(-1) in the vortex lattice state by Eilenberger theory, including the applied magnetic field dependence. We find that T-1(-1) in the NMR resonance line shape is different between two chiral states p +/-(= p(x)+/- ip(y)), depending on whether the chirality is parallel or antiparallel to the vorticity. Anomalous suppression of T-1(-1) occurs around the vortex core in the chiral p(-) wave due to the negative coherence term coming from the odd-frequency s-wave Cooper pair induced around the vortex with Majorana state.
備考 This is an article published by American Physical Society
発行日 2016-03
出版物タイトル Physical Review B
93巻
9号
出版者 American Physical Society
開始ページ 094507
ISSN 2469-9950
NCID AA11187113
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
著作権者 American Physical Society
論文のバージョン publisher
DOI 10.1103/PhysRevB.93.094507
Web of Sience KeyUT 000371727300005
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.93.094507
フルテキストURL PhysRevB_95_064512.pdf
著者 Ichioka, Masanori| Kogan, V. G.| Schmalian, J.|
抄録 A model of a clean two-band s-wave superconductor with cylindrical Fermi surfaces, different Fermi velocities v(1),(2), and a general 2x2 coupling matrix V-alpha beta is used to study the order parameter distribution in vortex lattices. The Eilenberger weak coupling formalism is used to calculate numerically the spatial distributions of the pairing amplitudes Delta(1) and Delta(2) of the two bands for vortices parallel to the Fermi cylinders. For generic values of the interband coupling V-12, it is shown that, independently of the couplings V-alpha beta, of the ratio v(1)/v(2), of the temperature, and the applied field, the length scales of spatial variation of Delta(1) and of Delta(2) are the same within the accuracy of our calculations. The only exception from this single length-scale behavior is found for V-12 << V-11, i.e., for nearly decoupled bands.
備考 This is an article published by American Physical Society
発行日 2017-02
出版物タイトル Physical Review B
95巻
6号
出版者 American Physical Society
開始ページ 064512
ISSN 2469-9950
NCID AA11187113
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
著作権者 ©2017 American Physical Society
論文のバージョン publisher
DOI 10.1103/PhysRevB.95.064512
Web of Sience KeyUT 000394657300012
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.95.064512
フルテキストURL PhysRevB_95_134502.pdf
著者 Tanaka, Kenta K.| Ichioka, Masanori| Onari, Seiichiro|
抄録 Properties of the vortex state in helical p-wave superconductor are studied by the quasiclassical Eilenberger theory. We confirm the instability of the helical p-wave state at high fields and that the spin-polarized local density of states M(E,r) appears even when Knight shift does not change. This is because the vorticity couples to the chirality of up-spin pair or down-spin pair of the helical state. In order to identify the helical p-wave state at low fields, we investigate the structure of the zero-energy M(E = 0,r) in the vortex states, and also the energy spectra of M(E,r).
備考 This is an article published by American Physical Society
発行日 2017-04
出版物タイトル Physical Review B
95巻
13号
出版者 American Physical Society
開始ページ 134502
ISSN 2469-9950
NCID AA11187113
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
著作権者 ©2017 American Physical Society
論文のバージョン publisher
DOI 10.1103/PhysRevB.95.134502
Web of Sience KeyUT 000399381300005
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.95.134502
フルテキストURL PhysRevB_96_094522.pdf
著者 Nabeta, Masahiro| Tanaka, Kenta K.| Onari, Seiichiro| Ichioka, Masanori|
抄録 The roles of paramagnetic and diamagnetic pair-breaking effects in superconductivity in the electric-field-induced surface metallic state are studied using the Bogoliubov–de Gennes equation when magnetic fields are applied parallel to the surface. The multigap states of the subbands are related to the depth dependence and the magnetic field dependence of the superconductivity. In the Fermi-energy density of states and the spin density, subband contributions successively appear from higher-level subbands with increasing magnetic fields. The characteristic magnetic field dependence may be a key feature to identify the multigap structure of the surface superconductivity.
備考 This is an article published by American Physical Society
発行日 2017-09
出版物タイトル Physical Review B
96巻
9号
出版者 American Physical Society
開始ページ 094522
NCID AA11187113
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
著作権者 ©2017 American Physical Society
論文のバージョン publisher
DOI 10.1103/PhysRevB.96.094522
Web of Sience KeyUT 000411161700006
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.96.094522