The Experts below are selected from a list of 100026 Experts worldwide ranked by ideXlab platform
Joseph A Stroscio - One of the best experts on this subject based on the ideXlab platform.
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experimental evidence for s wave pairing symmetry in superconducting cu x bi 2 se 3 single crystals using a scanning tunneling microscope
Physical Review Letters, 2013Co-Authors: Niv Levy, Tong Zhang, Jeonghoon Ha, Fred Sharifi, Alec A Talin, Joseph A StroscioAbstract:: Topological Superconductors represent a newly predicted phase of matter that is topologically distinct from conventional superconducting condensates of Cooper pairs. As a manifestation of their topological character, topological Superconductors support solid-state realizations of Majorana fermions at their boundaries. The recently discovered superconductor Cu(x)Bi(2)Se(3) has been theoretically proposed as an odd-parity superconductor in the time-reversal-invariant topological superconductor class, and point-contact spectroscopy measurements have reported the observation of zero-bias conductance peaks corresponding to Majorana states in this material. Here we report scanning tunneling microscopy measurements of the superconducting energy gap in Cu(x)Bi(2)Se(3) as a function of spatial position and applied magnetic field. The tunneling spectrum shows that the density of states at the Fermi level is fully gapped without any in-gap states. The spectrum is well described by the Bardeen-Cooper-Schrieffer theory with a momentum independent order parameter, which suggests that Cu(x)Bi(2)Se(3) is a classical s-wave superconductor contrary to previous expectations and measurements.
Erez Berg - One of the best experts on this subject based on the ideXlab platform.
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odd parity topological Superconductors theory and application to cu _x bi _2 se _3
Physical Review Letters, 2010Co-Authors: Liang Fu, Erez BergAbstract:Topological Superconductors have a full pairing gap in the bulk and gapless surface Andreev bound states. In this Letter, we provide a sufficient criterion for realizing time-reversal-invariant topological Superconductors in centrosymmetric Superconductors with odd-parity pairing. We next study the pairing symmetry of the newly discovered superconductor ${\mathrm{Cu}}_{x}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ within a two-orbital model, and find that a novel spin-triplet pairing with odd parity is favored by strong spin-orbit coupling. Based on our criterion, we propose that ${\mathrm{Cu}}_{x}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ is a good candidate for a topological superconductor. We close by discussing experimental signatures of this new topological phase.
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odd parity topological Superconductors theory and application to cuxbi2se3
Physical Review Letters, 2010Co-Authors: Erez BergAbstract:Topological Superconductors have a full pairing gap in the bulk and gapless surface Andreev bound states. In this Letter, we provide a sufficient criterion for realizing time-reversal-invariant topological Superconductors in centrosymmetric Superconductors with odd-parity pairing. We next study the pairing symmetry of the newly discovered superconductor ${\mathrm{Cu}}_{x}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ within a two-orbital model, and find that a novel spin-triplet pairing with odd parity is favored by strong spin-orbit coupling. Based on our criterion, we propose that ${\mathrm{Cu}}_{x}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ is a good candidate for a topological superconductor. We close by discussing experimental signatures of this new topological phase.
Liang Fu - One of the best experts on this subject based on the ideXlab platform.
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odd parity topological Superconductors theory and application to cu _x bi _2 se _3
Physical Review Letters, 2010Co-Authors: Liang Fu, Erez BergAbstract:Topological Superconductors have a full pairing gap in the bulk and gapless surface Andreev bound states. In this Letter, we provide a sufficient criterion for realizing time-reversal-invariant topological Superconductors in centrosymmetric Superconductors with odd-parity pairing. We next study the pairing symmetry of the newly discovered superconductor ${\mathrm{Cu}}_{x}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ within a two-orbital model, and find that a novel spin-triplet pairing with odd parity is favored by strong spin-orbit coupling. Based on our criterion, we propose that ${\mathrm{Cu}}_{x}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ is a good candidate for a topological superconductor. We close by discussing experimental signatures of this new topological phase.
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superconducting proximity effect and majorana fermions at the surface of a topological insulator
Physical Review Letters, 2008Co-Authors: Liang Fu, C L KaneAbstract:We study the proximity effect between an $s$-wave superconductor and the surface states of a strong topological insulator. The resulting two-dimensional state resembles a spinless ${p}_{x}+i{p}_{y}$ superconductor, but does not break time reversal symmetry. This state supports Majorana bound states at vortices. We show that linear junctions between Superconductors mediated by the topological insulator form a nonchiral one-dimensional wire for Majorana fermions, and that circuits formed from these junctions provide a method for creating, manipulating, and fusing Majorana bound states.
TERUO SASAGAWA - One of the best experts on this subject based on the ideXlab platform.
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antiferromagnetic order induced by an applied magnetic field in a high temperature superconductor
arXiv: Strongly Correlated Electrons, 2002Co-Authors: B Lake, H M Rønnow, N. B. Christensen, N. Mangkorntong, P. Smeibidl, D. F. Mcmorrow, Kim Lefmann, P. Vorderwisch, Gabriel Aeppli, TERUO SASAGAWAAbstract:One view of the cuprate high-transition temperature (high-Tc) Superconductors is that they are conventional Superconductors where the pairing occurs between weakly interacting quasiparticles, which stand in one-to-one correspondence with the electrons in ordinary metals - although the theory has to be pushed to its limit. An alternative view is that the electrons organize into collective textures (e.g. charge and spin stripes) which cannot be mapped onto the electrons in ordinary metals. The phase diagram, a complex function of various parameters (temperature, doping and magnetic field), should then be approached using quantum field theories of objects such as textures and strings, rather than point-like electrons. In an external magnetic field, magnetic flux penetrates type-II Superconductors via vortices, each carrying one flux quantum. The vortices form lattices of resistive material embedded in the non-resistive superconductor and can reveal the nature of the ground state - e.g. a conventional metal or an ordered, striped phase - which would have appeared had superconductivity not intervened. Knowledge of this ground state clearly provides the most appropriate starting point for a pairing theory. Here we report that for one high-Tc superconductor, the applied field which imposes the vortex lattice, also induces antiferromagnetic order. Ordinary quasiparticle pictures cannot account for the nearly field-independent antiferromagnetic transition temperature revealed by our measurements.
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Antiferromagnetic order induced by an applied magnetic field in a high-temperature superconductor.
Nature, 2002Co-Authors: B Lake, N Mangkorntongi, T Sasagawai, H M Rønnow, M Noharai, H Takagii, N. B. Christensen, N. Mangkorntong, P. Smeibidl, D. F. Mcmorrow, Kim Lefmann, P. Vorderwisch, Gabriel Aeppli, TERUO SASAGAWAAbstract:One view of the high-transition-temperature (high-Tc) copper oxide Superconductors is that they are conventional Superconductors where the pairing occurs between weakly interacting quasiparticles (corresponding to the electrons in ordinary metals), although the theory has to be pushed to its limit. An alternative view is that the electrons organize into collective textures (for example, charge and spin stripes) which cannot be 'mapped' onto the electrons in ordinary metals. Understanding the properties of the material would then need quantum field theories of objects such as textures and strings, rather than point-like electrons. In an external magnetic field, magnetic flux penetrates type II Superconductors via vortices, each carrying one flux quantum. The vortices form lattices of resistive material embedded in the non-resistive superconductor, and can reveal the nature of the ground state-for example, a conventional metal or an ordered, striped phase-which would have appeared had superconductivity not intervened, and which provides the best starting point for a pairing theory. Here we report that for one high-Tc superconductor, the applied field that imposes the vortex lattice also induces 'striped' antiferromagnetic order. Ordinary quasiparticle models can account for neither the strength of the order nor the nearly field-independent antiferromagnetic transition temperature observed in our measurements.
Asle Sudbo - One of the best experts on this subject based on the ideXlab platform.
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tunneling conductance and local density of states in time reversal symmetry breaking Superconductors under the influence of an external magnetic field
Physical Review B, 2009Co-Authors: Mihail Silaev, Takehito Yokoyama, Jacob Linder, Yukio Tanaka, Asle SudboAbstract:We consider different effects that arise when time-reversal symmetry breaking Superconductors are subjected to an external magnetic field, thus rendering the superconductor to be in the mixed state ...
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theory of andreev reflection in junctions with iron based high t c Superconductors
Physical Review B, 2009Co-Authors: Jacob Linder, Asle SudboAbstract:We construct a theory for low-energy quantum transport in $\text{normal}\ensuremath{\mid}\text{superconductor}$ junctions involving the recently discovered iron-based high-${T}_{c}$ Superconductors. We properly take into account both Andreev bound surface states and the complex Fermi-surface topology in our approach and investigate the signatures of the possible order-parameter symmetries for the FeAs lattice. Our results could be helpful in determining the symmetry of the superconducting state in the iron-pnicitide Superconductors.
