The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Masanori Hangyo - One of the best experts on this subject based on the ideXlab platform.
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Terahertz radiation imaging of vortices penetrated into YBCO thin films
IEEE Transactions on Applied Superconductivity, 2001Co-Authors: M. Tonouchi, Masatsugu Yamashita, A. Moto, Masanori HangyoAbstract:A Terahertz (THz) radiation and detection system with a scanning femtosecond (fs) laser is employed to visualize the Supercurrent distribution in vortex-penetrated YBCO thin films. This free-space, non contact, and nondestructive imaging system utilizes the principle that the fs optical pulses excite THz radiation into free-space and that the radiation amplitude is proportional to the local Supercurrent density at the excited area. The remanent states after removal of the Supercurrent biased to the thin film strips with and without ordered arrays of small antidots are examined and compared to the theoretical distributions. The THz radiation images are successfully transferred into the quantitative Supercurrent density distributions, which agrees with the theoretical predictions. The antidot effect is also discussed.
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Visualization of Supercurrent distribution by THz radiation mapping
Physica B-condensed Matter, 2000Co-Authors: Masatsugu Yamashita, Masayoshi Tonouchi, Masanori HangyoAbstract:Abstract We demonstrate imaging of Supercurrent distribution in YBCO thin-film strips using photoexcited terahertz (THz) radiation. The THz radiation images were successfully transferred into the Supercurrent density distributions in the strips under various conditions. The relationship between the detected THz radiation signals and the Supercurrent density is discussed.
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terahertz radiation imaging of Supercurrent distribution in vortex penetrated yba2cu3o7 δ thin film strips
Journal of Applied Physics, 2000Co-Authors: Masayoshi Tonouchi, Masatsugu Yamashita, Masanori HangyoAbstract:We have developed a Supercurrent distribution imaging system for high Tc superconductive thin films and demonstrated the visualization of the Supercurrent distribution in the vortex-penetrated YBa2Cu3O7−δ thin film strips. The terahertz (THz) radiation and detection system with a scanning femtosecond laser was employed to visualize the distribution. The imaging system utilizes the principle that the femtosecond optical pulses excite THz radiation into the free space by optical Supercurrent modulation, and the radiation amplitude is proportional to the local Supercurrent density at the optically excited area. Prior to the observation of the Supercurrent distribution, we studied optical excitation effects on the vortices trapped in the strips, calibration of the current density from the THz radiation amplitude, temperature dependence of the THz radiation properties, etc. The laser power dependence of the THz radiation in the remanent state revealed that the excitation with powers larger than the relatively ...
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Evaluation of Supercurrent Distribution by Terahertz Radiation Mapping
Advances in Superconductivity XI, 1999Co-Authors: Masatsugu Yamashita, Masayoshi Tonouchi, Shinichi Shikii, Takashi Kondo, Toshihiko Kiwa, Masanori HangyoAbstract:We propose and demonstrate a new visualization method of Supercurrent distribution in high-Tc superconducting films by mapping terahertz radiation. Using this method, we observed transport current distribution in YBCO thin films. Supercurrent flows near the edge of a YBCO strip line when the bias current is sufficiently small compared to the critical current. The distribution of the Supercurrent expands from the edge to the center of the strip line with increasing the bias current, which is qualitatively consistent with the Bean critical state model.
Fujio Shimizu - One of the best experts on this subject based on the ideXlab platform.
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persistent Supercurrent atom chip
Physical Review Letters, 2007Co-Authors: Tetsuya Mukai, Christoph Hufnagel, A Kasper, T Meno, A Tsukada, Kouichi Semba, Fujio ShimizuAbstract:Rubidium-87 atoms are trapped in an Ioffe-Pritchard potential generated with a persistent Supercurrent that flows in a loop circuit patterned on a sapphire surface. The superconducting circuit is a closed loop made of a 100 {mu}m wide molecular-beam epitaxy-grown MgB{sub 2} stripe carrying a Supercurrent of 2.5 A. To control the Supercurrent in the stripe, an on-chip thermal switch operated by a focused argon-ion laser is developed. The switch operates as an on/off switch of the Supercurrent or as a device to set the current to a specific value with the aid of an external magnetic field. The current can be set even without an external source if the change is in the decreasing direction.
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Trapping Atoms with a Persistent Supercurrent Atom Chip
2007 European Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference, 2007Co-Authors: Christoph Hufnagel, Tetsuya Mukai, Fujio ShimizuAbstract:In this presentation we report an achievement of a persistent Supercurrent atom chip and trapping 87Rb atoms in the vicinity of a cold surface. Persistent Supercurrent, up to 2.5 A without Joule heating, was switched on and off by using an on-chip thermal switch that was operated with a laser and a magnetic field. An intensity of the induced Supercurrent was controlled by the magnitude of the initially applied z-bias field. We present our experimental results on the characteristics of our atom trap including stability, decoherence time, and influence of the chip surface.
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Switching Persistent Supercurrent on an Atom Chip
2007 Conference on Lasers and Electro-Optics - Pacific Rim, 2007Co-Authors: Christoph Hufnagel, Tetsuya Mukai, Fujio ShimizuAbstract:Rubidium 87 atoms are trapped in an Ioffe-Pritchard potential generated with a persistent Supercurrent that flows in a loop circuit patterned on a sapphire surface. To control the Supercurrent on a surface, an on-chip thermal switch operated by a focused argon-ion laser is developed.
Sergei M Kuzenko - One of the best experts on this subject based on the ideXlab platform.
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Non-conformal Supercurrents in six dimensions
Journal of High Energy Physics, 2018Co-Authors: Sergei M Kuzenko, Joseph Novak, Stefan TheisenAbstract:Non-conformal Supercurrents in six dimensions are described, which contain the trace of the energy-momentum tensor and the gamma-trace of the supersymmetry current amongst their component fields. Within the superconformal approach to $$ \mathcal{N}=\left(1,\ 0\right) $$ supergravity, we present various distinct non-conformal Supercurrents, one of which is associated with an $$ \mathcal{O}(2) $$ (or linear) multiplet compensator, while another with a tensor multiplet compensator. We also derive an infinite class of non-conformal Supercurrents involving $$ \mathcal{O}(n) $$ multiplets with n > 2. As an illustrative example we construct the relaxed hypermultiplet in supergravity. Finally, we put forward a non-conformal Supercurrent in the $$ \mathcal{N}=\left(2,0\right) $$ supersymmetric case.
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a dual formulation of supergravity matter theories
Nuclear Physics, 2012Co-Authors: Daniel Butter, Sergei M KuzenkoAbstract:Generating supersymmetric AdS solutions in non-minimal supergravity in four dimensions is notoriously difficult. Indeed, it is a longstanding lore that such solutions exist only for old minimal supergravity. In this paper, we construct a dual formulation for general N=1 supergravity–matter systems that avoids the problem. In the case of pure supergravity without a cosmological constant, it coincides with the usual non-minimal (n=−1) supergravity, but in the presence of matter (or a cosmological constant) our formulation differs considerably. We also elaborate upon the framework of conformal superspace and the compensator method as applied to our theory. In particular, we show that one can encode the details of the Kahler potential and superpotential entirely within the geometry of superspace so that the general sigma-model action is encoded in a single compact term: the supervolume. Finally, we discuss the issue of Supercurrents and propose a general form for the Supercurrent in AdS.
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Variant Supercurrents and Noether procedure
European Physical Journal C, 2011Co-Authors: Sergei M KuzenkoAbstract:Consistent Supercurrent multiplets are naturally associated with linearized off-shell supergravity models. In S.M. Kuzenko, J. High Energy Phys. 1004, 022 (2010) we presented the hierarchy of such Supercurrents which correspond to all the models for linearized 4D \(\mathcal{N}=1\) supergravity classified a few years ago. Here we analyze the correspondence between the most general Supercurrent given in S.M. Kuzenko, J. High Energy Phys. 1004, 022 (2010) and the one obtained eight years ago in M. Magro et al., Ann. Phys. 298, 123 (2002) using the superfield Noether procedure. We apply the Noether procedure to the general \(\mathcal{N}=1\) supersymmetric nonlinear sigma-model and show that it naturally leads to the so-called \(\mathcal{S}\)-multiplet, revitalized in Z. Komargodski, N. Seiberg, J. High Energy Phys. 1007, 017 (2010).
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variant Supercurrent multiplets
Journal of High Energy Physics, 2010Co-Authors: Sergei M KuzenkoAbstract:In \( \mathcal{N} = 1 \) rigid supersymmetric theories, there exist three standard realizations of the Supercurrent multiplet corresponding to the (i) old minimal, (ii) new minimal and (iii) non-minimal off-shell formulations for \( \mathcal{N} = 1 \) supergravity. Recently, Komargodski and Seiberg in arXiv:1002.2228 put forward a new Supercurrent and proved its consistency, although in the past it was believed not to exist. In this paper, three new variant Supercurrent multiplets are proposed. Implications for supergravity-matter systems are discussed.
Masatsugu Yamashita - One of the best experts on this subject based on the ideXlab platform.
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Terahertz radiation imaging of vortices penetrated into YBCO thin films
IEEE Transactions on Applied Superconductivity, 2001Co-Authors: M. Tonouchi, Masatsugu Yamashita, A. Moto, Masanori HangyoAbstract:A Terahertz (THz) radiation and detection system with a scanning femtosecond (fs) laser is employed to visualize the Supercurrent distribution in vortex-penetrated YBCO thin films. This free-space, non contact, and nondestructive imaging system utilizes the principle that the fs optical pulses excite THz radiation into free-space and that the radiation amplitude is proportional to the local Supercurrent density at the excited area. The remanent states after removal of the Supercurrent biased to the thin film strips with and without ordered arrays of small antidots are examined and compared to the theoretical distributions. The THz radiation images are successfully transferred into the quantitative Supercurrent density distributions, which agrees with the theoretical predictions. The antidot effect is also discussed.
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Visualization of Supercurrent distribution by THz radiation mapping
Physica B-condensed Matter, 2000Co-Authors: Masatsugu Yamashita, Masayoshi Tonouchi, Masanori HangyoAbstract:Abstract We demonstrate imaging of Supercurrent distribution in YBCO thin-film strips using photoexcited terahertz (THz) radiation. The THz radiation images were successfully transferred into the Supercurrent density distributions in the strips under various conditions. The relationship between the detected THz radiation signals and the Supercurrent density is discussed.
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terahertz radiation imaging of Supercurrent distribution in vortex penetrated yba2cu3o7 δ thin film strips
Journal of Applied Physics, 2000Co-Authors: Masayoshi Tonouchi, Masatsugu Yamashita, Masanori HangyoAbstract:We have developed a Supercurrent distribution imaging system for high Tc superconductive thin films and demonstrated the visualization of the Supercurrent distribution in the vortex-penetrated YBa2Cu3O7−δ thin film strips. The terahertz (THz) radiation and detection system with a scanning femtosecond laser was employed to visualize the distribution. The imaging system utilizes the principle that the femtosecond optical pulses excite THz radiation into the free space by optical Supercurrent modulation, and the radiation amplitude is proportional to the local Supercurrent density at the optically excited area. Prior to the observation of the Supercurrent distribution, we studied optical excitation effects on the vortices trapped in the strips, calibration of the current density from the THz radiation amplitude, temperature dependence of the THz radiation properties, etc. The laser power dependence of the THz radiation in the remanent state revealed that the excitation with powers larger than the relatively ...
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Evaluation of Supercurrent Distribution by Terahertz Radiation Mapping
Advances in Superconductivity XI, 1999Co-Authors: Masatsugu Yamashita, Masayoshi Tonouchi, Shinichi Shikii, Takashi Kondo, Toshihiko Kiwa, Masanori HangyoAbstract:We propose and demonstrate a new visualization method of Supercurrent distribution in high-Tc superconducting films by mapping terahertz radiation. Using this method, we observed transport current distribution in YBCO thin films. Supercurrent flows near the edge of a YBCO strip line when the bias current is sufficiently small compared to the critical current. The distribution of the Supercurrent expands from the edge to the center of the strip line with increasing the bias current, which is qualitatively consistent with the Bean critical state model.
Masayoshi Tonouchi - One of the best experts on this subject based on the ideXlab platform.
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Visualization of Supercurrent distribution by THz radiation mapping
Physica B-condensed Matter, 2000Co-Authors: Masatsugu Yamashita, Masayoshi Tonouchi, Masanori HangyoAbstract:Abstract We demonstrate imaging of Supercurrent distribution in YBCO thin-film strips using photoexcited terahertz (THz) radiation. The THz radiation images were successfully transferred into the Supercurrent density distributions in the strips under various conditions. The relationship between the detected THz radiation signals and the Supercurrent density is discussed.
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terahertz radiation imaging of Supercurrent distribution in vortex penetrated yba2cu3o7 δ thin film strips
Journal of Applied Physics, 2000Co-Authors: Masayoshi Tonouchi, Masatsugu Yamashita, Masanori HangyoAbstract:We have developed a Supercurrent distribution imaging system for high Tc superconductive thin films and demonstrated the visualization of the Supercurrent distribution in the vortex-penetrated YBa2Cu3O7−δ thin film strips. The terahertz (THz) radiation and detection system with a scanning femtosecond laser was employed to visualize the distribution. The imaging system utilizes the principle that the femtosecond optical pulses excite THz radiation into the free space by optical Supercurrent modulation, and the radiation amplitude is proportional to the local Supercurrent density at the optically excited area. Prior to the observation of the Supercurrent distribution, we studied optical excitation effects on the vortices trapped in the strips, calibration of the current density from the THz radiation amplitude, temperature dependence of the THz radiation properties, etc. The laser power dependence of the THz radiation in the remanent state revealed that the excitation with powers larger than the relatively ...
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Evaluation of Supercurrent Distribution by Terahertz Radiation Mapping
Advances in Superconductivity XI, 1999Co-Authors: Masatsugu Yamashita, Masayoshi Tonouchi, Shinichi Shikii, Takashi Kondo, Toshihiko Kiwa, Masanori HangyoAbstract:We propose and demonstrate a new visualization method of Supercurrent distribution in high-Tc superconducting films by mapping terahertz radiation. Using this method, we observed transport current distribution in YBCO thin films. Supercurrent flows near the edge of a YBCO strip line when the bias current is sufficiently small compared to the critical current. The distribution of the Supercurrent expands from the edge to the center of the strip line with increasing the bias current, which is qualitatively consistent with the Bean critical state model.
