フルテキストURL PhysRevB_95_245310.pdf
著者 Uesugi, Eri| Miao, Xiao| Ota, Hiromi| Goto, Hidenori| Kubozono, Yoshihiro|
抄録 Field-effect transistors (FETs) were fabricated using exfoliated single crystals of Mo(Se1-x Te-x)(2) with an x range of 0 to 1, and the transistor properties fully investigated at 295 K in four-terminal measurement mode. The chemical composition and crystal structure of exfoliated single crystals were identified by energy-dispersive x-ray spectroscopy (EDX), single-crystal x-ray diffraction, and Raman scattering, suggesting the 2H - structure in all Mo(Se1-x Te-x)(2). The lattice constants of a and c increase monotonically with increasing x, indicating the substitution of Se by Te. When x < 0.4 in a FET with a thin single crystal of Mo(Se1-x Te-x)(2), n-channel FET properties were observed, changing to p-channelor ambipolar operation for x > 0.4. In contrast, the polarity of a thick single-crystal Mo(Se1-x Te-x)(2) FET did not change despite an increase in x. The change of polarity in a thin single-crystal FET was well explained by the variation of electronic structure. The absence of such change in the thick single-crystal FET can be reasonably interpreted based on the large bulk conduction due to naturally accumulated electrons. The mu value in the thin single-crystal FET showed a parabolic variation, with a minimum mu at around x = 0.4, which probably originates from the disorder of the single crystal caused by the partial replacement of Se by Te, i.e., a disorder that may be due to ionic size difference of Se and Te.
備考 This is an article published by American Physical Society
発行日 2017-01
出版物タイトル Physical Review B
95巻
24号
出版者 American Physical Society
開始ページ 245310
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.95.245310
Web of Sience KeyUT 000403355300005
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.95.245310
フルテキストURL PhysRevA_84_011607.pdf
著者 Kawakami, Takuto| Mizushima, Takeshi| Machida, Kazushige|
抄録 We study the textures of F = 2 spinor Bose-Einstein condensates (BECs) with spin-orbit coupling (SOC) induced by a synthetic non-Abelian gauge field. On the basis of the analysis of the SOC energy and the numerical calculation of the Gross-Pitaevskii equation, we demonstrate that the textures originate from the helical modulation of the order parameter (OP) due to the SOC. In particular, the cyclic OP consists of two-dimensional lattice textures, such as the hexagonal lattice and the 1/3 vortex lattice, commonly understandable as the two-dimensional network of the helical modulations.
備考 This is an article published by American Physical Society
発行日 2011-07
出版物タイトル Physical Review A
84巻
1号
出版者 American Physical Society
開始ページ 011607
ISSN 2469-9926
NCID AA10764867
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/PhysRevA.84.011607
Web of Sience KeyUT 000293126500002
関連URL isVersionOf https://doi.org/10.1103/PhysRevA.84.011607
フルテキストURL PhysRevB_97_094525.pdf
著者 Terashima, K.| Paris, E.| Simonelli, L.| Salas-Colera, E.| Puri, A.| Wakita, T.| Yamada, Y.| Nakano, S.| Idei, H.| Kudo, K.| Nohara, M.| Muraoka, Y.| Mizokawa, T.| Yokoya, T.| Saini, N. L.|
抄録 The local structures of 122-type paradium arsenides, namely BaPd2As2 and SrPd2As2, are examined by As K-edge extended x-ray absorption fine structure measurements to find a possible correlation between the variation of their superconducting transition temperature and the local structure. The local atomic distances are found to be consistent with average distances measured by diffraction techniques. The temperature dependence of mean square relative displacements reveal that, while BaPd2As2 is characterized by a local As-Pd soft mode, albeit with larger atomic disorder, SrPd2As2 shows anomalous As-Pd correlations with a kink at similar to 160 K due to hardening by raising temperature. We have discussed implications of these results and possible mechanisms of differing superconducting transition temperature in relation with the structural instability.
備考 This is an article published by American Physical Society
発行日 2018-09-28
出版物タイトル Physical Review B
98巻
9号
出版者 American Physical Society
開始ページ 094525
ISSN 24699950
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.98.094525
Web of Sience KeyUT 000446178800008
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.98.094525
フルテキストURL PhysRevB_94_174505.pdf
著者 Zheng, Lu| Sakai, Yusuke| Miao, Xiao| Nishiyama, Saki| Terao, Takahiro| Eguchi,, Ritsuko| Goto, Hidenori| Kubozono, Yoshihiro|
抄録 Na-intercalated FeSe0.5Te0.5 was prepared using the liquid NH3 technique, and a superconducting phase exhibiting a superconducting transition temperature (T-c) as high as 27 K was discovered. This can be called the high-T-c phase since a 21 K superconducting phase was previously obtained in (NH3)(y)NaxFeSe0.5Te0.5. The chemical composition of the high-T-c phase was determined to be (NH3)(0.61(4))Na-0.63(5) Fe0.85Se0.55(3) Te-0.44(2). The x-ray diffraction patterns of both phases show that a larger lattice constant c (i.e., FeSe0.5Te0.5 plane spacing) produces a higher T-c. This behavior is the same as that of metal-doped FeSe, suggesting that improved Fermi-surface nesting produces the higher T-c. The high-T-c phase converted to the low-T-c phase within several days, indicating that it is a metastable phase. The temperature dependence of resistance for both phases was recorded at different magnetic fields, and the critical fields were determined for both phases. Finally, the T-c versus c phase diagram was prepared for the metal-doped FeSe0.5Te0.5, which is similar to that of metal-doped FeSe, although the T-c is lower.
備考 This is an article published by American Physical Society
発行日 2016-11
出版物タイトル Physical Review B
94巻
17号
出版者 American Physical Society
開始ページ 174505
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.94.174505
Web of Sience KeyUT 000387884100004
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.94.174505
フルテキストURL PhysRevA_82_023624.pdf
著者 Mizushima, T.| Machida, K.|
抄録 We investigate how the vortex-vortex separation changes Majorana zero modes in the vicinity of the BCS-BEC (Bose-Einstein condensation) topological phase transition of p-wave resonant Fermi gases. By analytically and numerically solving the Bogoliubov-de Gennes equation for spinless p-wave superfluids with plural vortices, it is demonstrated that the quasiparticle tunneling between neighboring vortices gives rise to the quantum oscillation of the low-lying spectra on the scale of the Fermi wavelength in addition to the exponential splitting. This rapid oscillation, which appears in the weak-coupling regime as a consequence of quantum oscillations of quasiparticle wave functions, disappears in the vicinity of the BCS-BEC topological phase transition. This is understandable from that the wave function of the Majorana zero modes is described by the modified Bessel function in the strong-coupling regime, and thus it becomes spread over the vortex core region. Due to the exponential divergence of the modified Bessel function, the concrete realization of the Majorana zero modes near the topological phase transition requires the neighboring vortices to be separated beyond the length scale defined by the coherence length and the dimensionless coupling constant. All these behaviors are also confirmed by carrying out the full numerical diagonalization of the nonlocal Bogoliubov-de Gennes equation in a two-dimensional geometry. Furthermore, this argument is expanded into the case of three-vortex systems, where a pair of core-bound and edge-bound Majorana states survive at zero-energy state regardless of the vortex separation.
備考 This is an article published by American Physical Society
発行日 2010-08
出版物タイトル Physical Review A
82巻
2号
出版者 American Physical Society
開始ページ 023624
ISSN 1050-2947
NCID AA10764867
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/PhysRevA.82.023624
Web of Sience KeyUT 000281405500012
関連URL isVersionOf https://doi.org/10.1103/PhysRevA.82.023624
フルテキストURL PhysRevB_96_104502.pdf
著者 Maeda, Satoki| Hirose, Ryohei| Matano, Kazuaki| Novak, Mario| Ando, Yoichi| Zheng, Guo-qing|
抄録 The In-doped topological crystalline insulator Sn1−x InxTe is a candidate for a topological superconductor, where a pseudo-spin-triplet state has been proposed. To clarify the spin symmetry of Sn1−x InxTe, we perform 125Te-nuclear magnetic resonance (NMR) measurements in polycrystalline samples with 0 x 0.15. The penetration depth calculated from the NMR line width is T independent below half the superconducting transition temperature (Tc) in polycrystalline Sn0.96In0.04Te, which indicates a fully opened superconducting gap. In this sample, the spin susceptibility measured by the spin Knight shift (Ks) at an external magnetic field of μ0H0 = 0.0872 T decreases below Tc, and Ks(T = 0)/Ks(T = Tc) reaches 0.36 ± 0.10, which is far below the limiting value 2/3 expected for a spin-triplet state for a cubic crystal structure. Our result indicates that polycrystalline Sn0.96In0.04Te is a spin-singlet superconductor.
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
10号
出版者 American Physical Society
開始ページ 104502
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.96.104502
Web of Sience KeyUT 000409253700007
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.96.104502
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 PhysRevA_81_063623.pdf
著者 Huhtamaki, J. A. M.| Takahashi, M.| Simula, T. P.| Mizushima, T.| Machida, K.|
抄録 We have solved numerically the ground states of a Bose-Einstein condensate in the presence of dipolar interparticle forces using a semiclassical approach. Our motivation is to model, in particular, the spontaneous spin textures emerging in quantum gases with large dipole moments, such as Cr-52 or Dy condensates, or ultracold gases consisting of polar molecules. For a pancake-shaped harmonic ( optical) potential, we present the ground-state phase diagram spanned by the strength of the nonlinear coupling and dipolar interactions. In an elongated harmonic potential, we observe a helical spin texture. The textures calculated according to the semiclassical model in the absence of external polarizing fields are predominantly analogous to previously reported results for a ferromagnetic F = 1 spinor Bose-Einstein condensate, suggesting that the spin textures arising from the dipolar forces are largely independent of the value of the quantum number F or the origin of the dipolar interactions.
備考 This is an article published by American Physical Society
発行日 2010-06-14
出版物タイトル Physical Review A
81巻
6号
出版者 American Physical Society
開始ページ 063623
ISSN 24699926
NCID AA10764867
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/PhysRevA.81.063623
Web of Sience KeyUT 000278719500005
関連URL isVersionOf https://doi.org/10.1103/PhysRevA.81.063623
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 PhysRevE_91_016302.pdf
著者 Yagasaki, Takuma| Matsumoto, Masakazu| Tanaka, Hideki|
抄録 Two different scenarios have been proposed on the phase separation occurring in the deeply supercooled liquid water. We discuss what we can derive from our simulation results for the two scenarios and propose a way for future investigation. We also demonstrate that the phase separation in the supercooled liquid water looks like the separation of liquid water and vapor just below the conventional critical point.
発行日 2015-01-23
出版物タイトル Physical review. E, Statistical, nonlinear, and soft matter physics
91巻
1号
出版者 American Physical Society
開始ページ 016302
ISSN 1539-3755
NCID AA11558033
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 https://creativecommons.org/licenses/by-nc-nd/4.0/deed.ja
論文のバージョン publisher
PubMed ID 25679745
DOI 10.1103/PhysRevE.91.016302
Web of Sience KeyUT 000349487700008
関連URL https://doi.org/10.1103/PhysRevE.91.016302
フルテキストURL PhysRevB_97_104503.pdf
著者 He, Tong| Yang, Xiaofan| Terao, Takahiro| Uchiyama, Takaki| Ueno, Teppei| Kobayashi, Kaya| Akimitsu, Jun| Miyazaki, Takafumi| Nishioka, Takumi| Kimura, Koji| Hayashi, Kouichi| Happo, Naohisa| Yamaoka, Hitoshi| Ishii, Hirofumi| Liao, Yen-Fa| Ota, Hiromi| Goto, Hidenori| Kubozono, Yoshihiro|
抄録 We investigated the pressure dependence of electric transport and crystal structure of Ag-doped Bi2Se3. In the sample prepared by Ag doping of Bi2Se3, the Bi atom was partially replaced by Ag, i.e., Ag0.05Bi1.95Se3. X-ray diffraction patterns of Ag0.05Bi1.95Se3 measured at 0–30 GPa showed three different structural phases, with rhombohedral, monoclinic, and tetragonal structures forming in turn as pressure increased, and structural phase transitions at 8.8 and 24 GPa. Ag0.05Bi1.95Se3 showed no superconductivity down to 2.0 K at 0 GPa, but under pressure, superconductivity suddenly appeared at 11 GPa. The magnetic field (H) dependence of the superconducting transition temperature Tc was measured at 11 and 20.5 GPa, in order to investigate whether the pressure-induced superconducting phase is explained by either p-wave polar model or s-wave model.
備考 This is an article published by American Physical Society This study was partly supported by Grants-in-Aid (Grants No. 26105004 and No. 17K05500) from MEXT, by JST ACT-C Grant No. JPMJCR12YW
発行日 2018-03-07
出版物タイトル Physical Review B
97巻
10号
出版者 American Physical Society
開始ページ 104503
ISSN 01631829
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.97.104503
Web of Sience KeyUT 000426776800003
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.97.104503
フルテキストURL PhysRevB_97_094505.pdf
著者 Terao, Takahiro| Yang, Xiaofan| Miao, Xiao| Zheng, Lu| Goto, Hidenori| Miyazaki, Takafumi| Yamaoka, Hitoshi| Ishii, Hirofumi| Liao, Yen-Fa| Kubozono, Yoshihiro|
抄録 We prepared two superconducting phases, which are called “low-Tc phase” and “high-Tc phase” of (NH3)yNaxFeSe showing Tc’s of 35 and 44 K, respectively, at ambient pressure, and studied the superconducting behavior and structure of each phase under pressure. The Tc of the 35 K at ambient pressure rapidly decreases with increasing pressure up to 10 GPa, and it remains unchanged up to 22 GPa. Finally, superconductivity was not observed down to 1.4 K at 29 GPa, i.e., Tc < 1.4K. The Tc of the 44 K phase also shows a monotonic decrease up to 15 GPa and it weakly decreases up to 25 GPa. These behaviors suggest no pressure-driven high-Tc phase (called “SC-II”) between 0 and 25 GPa for the low-Tc and high-Tc phases of (NH3)yNaxFeSe, differing from the behavior of (NH3)yCsxFeSe,which has a pressure-driven high-Tc phase (SC-II) in addition to the superconducting phase (SC-I) observed at ambient and low pressures. The Tc-c phase diagram for both low-Tc and high-Tc phases shows that the Tc can be linearly scaled with c (or FeSe plane spacing), where c is a lattice constant. The reason why a pressure-driven high-Tc phase (SC-II) was found for neither low-Tc nor high-Tc phases of (NH3)yNaxFeSe is fully discussed, suggesting a critical c value as the key to forming the pressure-driven high-Tc phase (SC-II). Finally, the precise Tc-c phase diagram is depicted using the data obtained thus far from FeSe codoped with a metal and NH3 or amine, indicating two distinct Tc-c lines below c = 17.5A° .
キーワード Superconductors 2-dimensional systems 4-terminal techniques Pressure effects X-ray diffraction
備考 This is an article published by American Physical Society This study was partly supported by Grants-in-Aid (26105004 and 26400361) from MEXT, by JST ACT-C Grant No. JPMJCR12YW, Japan, and by the Program for Promoting the Enhancement of Research Universities.
発行日 2018-03-09
出版物タイトル Physical Review B
97巻
9号
出版者 American Physical Society
開始ページ 094505
ISSN 01631829
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.97.094505
Web of Sience KeyUT 000427010000003
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.97.094505
フルテキストURL PhysRevB_96_014502.pdf
著者 Miao, Xiao| Terao, Takahiro| Yang, Xiaofan| Nishiyama, Saki| Miyazaki, Takafumi| Goto, Hidenori| Iwasa, Yoshihiro| Kubozono, Yoshihiro|
抄録 We have studied new superconductors prepared by metal doping of two-dimensional (2D) layered materials, FeSe and FeSe0.5Te0.5, using ethylenediamine (EDA). The superconducting transition temperatures (T(c)s) of metal-doped FeSe and metal-doped FeSe0.5Te0.5, i.e., (EDA)(y)MxFeSe and (EDA)(y)MxFeSe0.5Te0.5 (M: Li, Na, and K), were 31-45 K and 19-25 K, respectively. The stoichiometry of each sample was clarified by energy dispersive x-ray (EDX) spectroscopy, and the x-ray powder diffraction pattern indicated a large expansion of lattice constant c, indicating the cointercalation of metal atoms and EDA. The pressure dependence of superconductivity in (EDA)(y)NaxFeSe0.5Te0.5 has been investigated at a pressure of 0-0.8GPa, showing negative pressure dependence in the same manner as (NH3)(y)NaxFeSe0.5Te0.5. The T-c-c phase diagrams of MxFeSe and MxFeSe0.5Te0.5 were drawn afresh from the T-c and c of (EDA)(y)MxFeSe and (EDA)(y)MxFeSe0.5Te0.5, showing that the T-c increases with increasing c but that extreme expansion of c reverses the T-c trend.
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
1号
出版者 American Physical Society
開始ページ 014502
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.96.014502
Web of Sience KeyUT 000405020200010
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.96.014502
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
フルテキストURL PhysRevB_97_064425.pdf
著者 Horigane, Kazumasa| Fujii, M.| Okabe, H.| Kobayashi, K.| Horie, R.| Ishii, H.| Liao, Y. F.| Kubozono, Y.| Koda, A.| Kadono, R.| Akimitsu, J.|
抄録 We report the crystal structure and physical properties of Sr2-xLaxIrO4 synthesized by mechanical alloying. The magnetic transition temperature T-N and electrical resistivity decreased with increasing La doping, consistent with previous studies involving single-crystalline samples. We also identified the relationship between T-N and tetragonal distortion (c/a) in this system. This result suggests that the magnetism of the Sr214 system is strongly correlated with its crystal structure. Zero-field muon spin rotation/relaxation studies revealed that short-range antiferromagnetic ordering is realized in Sr1.9La0.1IrO4; also, the spin-glass state is stabilized in the low-temperature region. The Ir moment estimated from the longitudinal field mu SR results is 0.045 mu(B), ten times smaller than that of Sr2IrO4 (similar to 0.4 mu(B)), indicating that electrons are introduced into the Ir atoms.
備考 This is an article published by American Physical Society
発行日 2018-02-28
出版物タイトル Physical Review B
97巻
出版者 American Physical Society
開始ページ 064425
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.97.064425
Web of Sience KeyUT 000426321000005
関連URL isVersionOf https://doi.org/10.1103/PhysRevB.97.064425
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_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_094527.pdf
著者 Onari, Seiichiro| Kontani, Hiroshi|
抄録 The origin of the electronic nematicity and its remarkable material dependence are famous longstanding unsolved issues in Fe-based superconductors. To attack these issues, we focus on the in-plane anisotropy of the resistivity: In the nematic state in FeSe, the relationp(x) >p(y) holds, whereP(x)(y) is the resistivity along the longer (shorter) Fe-Fe axis. In contrast, the opposite anisotropy p(x) < p(y) is realized in other undoped Fe-based superconductors. Such nontrivial material dependence is naturally explained in terms of the strongly orbitaldependent inelastic quasiparticle scattering realized in the orbital-ordered state. The opposite anisotropy between FeSe (p(x) >p(y)) and other undoped compounds (P-x < P-y) reflects the difference in the number of hole pockets. We also explain the large in-plane anisotropy of the thermoelectric power in the nematic state.
備考 This is an article published by American Physical Society
発行日 2017-09-26
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 094527
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.96.094527
Web of Sience KeyUT 000411768000002
関連URL isVersionOf http://doi.org/10.1103/PhysRevB.96.094527
フルテキストURL PhysRevA_96_063827.pdf
著者 Hara, Hideaki| Miyamoto, Yuki| Hiraki, Takahiro| Masuda, Takahiko| Sasao, Noboru| Uetake, Satoshi| Yoshimi, Akihiro| Yoshimura, Koji| Yoshimura, Motohiko|
抄録 We investigate how the efficiency of coherently amplified two-photon emission depends on the frequency of one of the two emitted photons, namely the signal photon. This is done over the wavelength range of 5.048-10.21 mu m by using the vibrational transition of parahydrogen. The efficiency increases with the frequency of the signal photon. Considering experimental errors, our results are consistent with the theoretical prediction for the present experimental conditions. This study is an experimental demonstration of the frequency dependence of coherently amplified two-photon emission, and also presents its potential as a light source.
備考 This is an article published by American Physical Society
発行日 2017-12
出版物タイトル Physical Review A
96巻
6号
出版者 American Physical Society
開始ページ 063827
ISSN 2469-9926
NCID AA10764867
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/PhysRevA.96.063827
Web of Sience KeyUT 000418297700009
関連URL isVersionOf https://doi.org/10.1103/PhysRevA.96.063827