arXiv: Superconductivity最新文献_第5页

Yu-Shiba-Rusinov bound states studied by tuning the electron density at the Fermi energy 通过调整费米能量处的电子密度来研究Yu-Shiba-Rusinov束缚态

arXiv: Superconductivity Pub Date : 2020-10-20 DOI: 10.1103/PhysRevB.103.214509

S. Song, Yoon Sung Park, Yongchan Jeong, Min-Seok Kim, Ki-Seok Kim, Jungpil Seo

引用次数: 2

Temporarily enhanced superconductivity from magnetic fields 磁场暂时增强的超导性

arXiv: Superconductivity Pub Date : 2020-10-19 DOI: 10.1103/PHYSREVB.103.L100502

Eirik Holm Fyhn, J. Linder

引用次数: 1

Signatures of triplet correlations in density of states of Ising superconductors 伊辛超导体态密度中三重态相关的特征

arXiv: Superconductivity Pub Date : 2020-10-16 DOI: 10.1103/physrevb.102.214513

M. Haim, D. Möckli, M. Khodas

{"title":"Signatures of triplet correlations in density of states of Ising superconductors","authors":"M. Haim, D. Möckli, M. Khodas","doi":"10.1103/physrevb.102.214513","DOIUrl":"https://doi.org/10.1103/physrevb.102.214513","url":null,"abstract":"The few-layer transition metal dichalcogenides (TMDs) have been recently suggested as a platform for controlled unconventional superconductivity. We study the manifestations of unconventional triplet pairing in the density of states of a disordered TMD based monolayer. The conventional singlet pairing attraction is assumed to be the dominant pairing interaction. We map the phase diagrams of disordered Ising superconductors in the plane of temperature and the in-plane magnetic field. The latter suppresses singlet and promote triplet correlations. The triplet order parameters of a trivial (non-trivial) symmetry compete (cooperate) with the singlet order parameter which gives rise to a rich phase diagram. We locate the model-dependent phase boundaries and compute the order parameters in each of the distinct phases. With this information, we obtain the density of states by solving the Gorkov equation. The triplet components of the order parameters may change an apparent width of the density of states by significantly increasing the critical field. The triplet components of the order parameters lead to the density of states broadening significantly exceeding the broadening induced by magnetic field and disorder in the singlet superconductor.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75544250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Effect of spin fluctuations on superconductivity in V and Nb: A first-principles study 自旋涨落对V和Nb超导性的影响:第一性原理研究

arXiv: Superconductivity Pub Date : 2020-10-14 DOI: 10.1103/physrevb.102.214515

K. Tsutsumi, Yuma Hizume, M. Kawamura, R. Akashi, S. Tsuneyuki

引用次数: 1

Influence of substrate-induced thermal stress on the superconducting properties of V 3 Si thin films 衬底诱导热应力对v3si薄膜超导性能的影响

arXiv: Superconductivity Pub Date : 2020-10-14 DOI: 10.1063/5.0038638

T. Vethaak, F. Gustavo, T. Farjot, T. Kubart, P. Gergaud, S. Zhang, F. Nemouchi, F. Lefloch

{"title":"Influence of substrate-induced thermal stress on the superconducting properties of V 3 Si thin films","authors":"T. Vethaak, F. Gustavo, T. Farjot, T. Kubart, P. Gergaud, S. Zhang, F. Nemouchi, F. Lefloch","doi":"10.1063/5.0038638","DOIUrl":"https://doi.org/10.1063/5.0038638","url":null,"abstract":"Thin films of superconducting V$_3$Si were prepared by means of RF sputtering from a compound V$_3$Si target at room temperature onto sapphire and oxide-coated silicon wafers, followed by rapid thermal processing under secondary vacuum. The superconducting properties of the films thus produced are found to improve with annealing temperature, which is ascribed to a reduction of defects in the polycrystalline layer. Critical temperatures ($T_text{c}$) up to $15.3,$K were demonstrated after thermal processing, compared to less than $1,$K after deposition. The $T_text{c}$ was found to always be lower on the silicon wafers, by on average $1.9(3),$K for the annealed samples. This difference, as well as a broadening of the superconducting transitions, is nearly independent of the annealing conditions. In-situ XRD measurements reveal that the silicide layer becomes strained upon heating due to a mismatch between the thermal expansion of the substrate and that of V$_3$Si. Taking into account the volume reduction due to crystallization, this mismatch is initially larger on sapphire, though stress relaxation allows the silicide layer to be in a relatively unstrained state after cooling. On oxidized silicon however, no clear evidence of relaxation upon cooling is observed, and the V$_3$Si ends up with an out-of-plane strain of 0.3% at room temperature. This strain increases as the sample is cooled down to cryogenic temperatures, though the deformation of the polycrystalline layer is expected to be highly inhomogeneous. Taking into account also the reported occurrence of a Martensitic transition just above the critical temperature, this extrapolated strain distribution is found to closely match an existing model of the strain dependence of A-15 superconducting compounds.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"214 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77558677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Magnetic response of Majorana Kramers pairs with an order-two symmetry 具有二阶对称的Majorana Kramers对的磁响应

arXiv: Superconductivity Pub Date : 2020-10-13 DOI: 10.1103/PHYSREVB.103.094508

Y. Yamazaki, S. Kobayashi, A. Yamakage

引用次数: 2

Faithful derivation of symmetry indicators: A case study for topological superconductors with time-reversal and inversion symmetries 对称指标的忠实推导:具有时间反转和反转对称性的拓扑超导体的一个案例研究

arXiv: Superconductivity Pub Date : 2020-10-12 DOI: 10.1103/PHYSREVRESEARCH.3.013243

Sheng-Jie Huang, Yi-Ting Hsu

{"title":"Faithful derivation of symmetry indicators: A case study for topological superconductors with time-reversal and inversion symmetries","authors":"Sheng-Jie Huang, Yi-Ting Hsu","doi":"10.1103/PHYSREVRESEARCH.3.013243","DOIUrl":"https://doi.org/10.1103/PHYSREVRESEARCH.3.013243","url":null,"abstract":"Topological crystalline superconductors have attracted rapidly rising attention due to the possibility of higher-order phases, which support Majorana modes on boundaries in $d-2$ or lower dimensions. However, although the classification and bulk topological invariants in such systems have been well studied, it is generally difficult to faithfully predict the boundary Majoranas from the band-structure information due to the lack of well-established bulk-boundary correspondence. Here we propose a protocol for deriving symmetry indicators that depend on a minimal set of necessary symmetry data of the bulk bands and can diagnose boundary features. Specifically, to obtain indicators manifesting clear bulk-boundary correspondence, we combine the topological crystal classification scheme in the real space and a twisted equivariant K group analysis in the momentum space. The key step is to disentangle the generally mixed strong and weak indicators through a systematic basis-matching procedure between our real-space and momentum-space approaches. We demonstrate our protocol using an example of two-dimensional time-reversal odd-parity superconductors, where the inversion symmetry is known to protect a higher-order phase with corner Majoranas. Symmetry indicators derived from our protocol can be readily applied to ab initio database and could fuel material predictions for strong and weak topological crystalline superconductors with various boundary features.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78884026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

Artificial graphene: Unconventional superconductivity in a honeycomb superlattice 人造石墨烯:蜂窝超晶格中的非常规超导性

arXiv: Superconductivity Pub Date : 2020-10-12 DOI: 10.1103/physrevresearch.2.043155

Tommy Li, J. Ingham, H. Scammell

{"title":"Artificial graphene: Unconventional superconductivity in a honeycomb superlattice","authors":"Tommy Li, J. Ingham, H. Scammell","doi":"10.1103/physrevresearch.2.043155","DOIUrl":"https://doi.org/10.1103/physrevresearch.2.043155","url":null,"abstract":"Artificial lattices have served as a platform to study the physics of unconventional superconductivity. We study semiconductor artificial graphene -- a honeycomb superlattice imposed on a semiconductor heterostructure -- which hosts the Dirac physics of graphene but with a tunable periodic potential strength and lattice spacing, allowing control of the strength of the electron-electron interactions. We demonstrate a new mechanism for superconductivity due to repulsive interactions which requires a strong lattice potential and a minimum doping away from the Dirac points. The mechanism relies on the Berry phase of the emergent Dirac fermions, which causes oppositely moving electron pairs near the Dirac points to interfere destructively, reducing the Coulomb repulsion and thereby giving rise to an effective attraction. The attractive component of the interaction is enhanced by a novel antiscreening effect which, in turn, increases with doping; as a result there is a minimum doping beyond which superconducting order generically ensues. The dominant superconducting state exhibits a spatially modulated gap with chiral $p$-wave symmetry. Microscopic calculations suggest that the possible critical temperatures are large relative to the low carrier densities, for a range of experimentally realistic parameters.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90174606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

Capping layer influence and isotropic in-plane upper critical field of the superconductivity at the FeSe/SrTiO3 interface 封盖层对FeSe/SrTiO3界面超导性的影响及面内各向同性上临界场

arXiv: Superconductivity Pub Date : 2020-10-11 DOI: 10.1103/PHYSREVMATERIALS.5.034802

Yanan Li, Ziqiao Wang, Run Xiao, Qi Li, Ke Wang, A. Richardella, Jian Wang, N. Samarth

{"title":"Capping layer influence and isotropic in-plane upper critical field of the superconductivity at the \u0000FeSe/SrTiO3\u0000 interface","authors":"Yanan Li, Ziqiao Wang, Run Xiao, Qi Li, Ke Wang, A. Richardella, Jian Wang, N. Samarth","doi":"10.1103/PHYSREVMATERIALS.5.034802","DOIUrl":"https://doi.org/10.1103/PHYSREVMATERIALS.5.034802","url":null,"abstract":"Understanding the superconductivity at the interface of FeSe/SrTiO3 is a problem of great contemporary interest due to the significant increase in critical temperature (Tc) compared to that of bulk FeSe, as well as the possibility of an unconventional pairing mechanism and topological superconductivity. We report a study of the influence of a capping layer on superconductivity in thin films of FeSe grown on SrTiO3 using molecular beam epitaxy. We used in vacuo four-probe electrical resistance measurements and ex situ magneto-transport measurements to examine the effect of three capping layers that provide distinctly different charge transfer into FeSe: compound FeTe, non-metallic Te, and metallic Zr. Our results show that FeTe provides an optimal cap that barely influences the inherent Tc found in pristine FeSe/SrTiO3, while the transfer of holes from a non-metallic Te cap completely suppresses superconductivity and leads to insulating behavior. Finally, we used ex situ magnetoresistance measurements in FeTe-capped FeSe films to extract the angular dependence of the in-plane upper critical magnetic field. Our observations reveal an almost isotropic in-plane upper critical field, providing insight into the symmetry and pairing mechanism of high temperature superconductivity in FeSe.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77733854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Current-phase relation in a topological Josephson junction: Andreev bands versus scattering states 拓扑Josephson结的电流相关系:Andreev带与散射态

arXiv: Superconductivity Pub Date : 2020-10-07 DOI: 10.1103/PHYSREVB.103.115423

S. Backens, A. Shnirman

引用次数: 1