arXiv: Superconductivity最新文献_第7页

Superconductivity of underdoped PrFeAs(O,F) investigated via point-contact spectroscopy and nuclear magnetic resonance 利用点接触光谱和核磁共振技术研究了欠掺杂PrFeAs(O,F)的超导性

arXiv: Superconductivity Pub Date : 2020-09-10 DOI: 10.1103/PhysRevB.102.104513

D. Daghero, E. Piatti, Nikolai Zhigadlo, G. Ummarino, N. Barbero, T. Shiroka

引用次数: 5

Imprint of charge and oxygen orders on Dy ions in DyBa2Cu3O6+x thin films probed by resonant x-ray scattering 共振x射线散射探测DyBa2Cu3O6+x薄膜中Dy离子的电荷和氧序压印

arXiv: Superconductivity Pub Date : 2020-09-08 DOI: 10.1103/physrevb.102.195149

D. Betto, M. Bluschke, D. Putzky, E. Schierle, A. Amorese, K. Fursich, S. Blanco-Canosa, G. Christiani, G. Logvenov, B. Keimer, M. Minola

引用次数: 1

Anomalous softening of phonon dispersion in cuprate superconductors 铜超导体中声子色散的反常软化

arXiv: Superconductivity Pub Date : 2020-09-07 DOI: 10.1103/PHYSREVRESEARCH.3.013162

Saheli Sarkar, M. Grandadam, C. P'epin

引用次数: 3

Two-gap to Single-gap Superconducting Transition on a Honeycomb Lattice in Ca$_{1-x}$Sr$_{x}$AlSi Ca$ {1-x}$Sr$ {x}$AlSi中蜂窝晶格的双间隙到单间隙超导跃迁

arXiv: Superconductivity Pub Date : 2020-09-04 DOI: 10.1103/PhysRevResearch.3.033192

Dorota I. Walicka, Z. Guguchia, J. Lago, O. Blacque, K. Ma, R. Khasanov, F. O. Rohr

{"title":"Two-gap to Single-gap Superconducting Transition on a Honeycomb Lattice in Ca$_{1-x}$Sr$_{x}$AlSi","authors":"Dorota I. Walicka, Z. Guguchia, J. Lago, O. Blacque, K. Ma, R. Khasanov, F. O. Rohr","doi":"10.1103/PhysRevResearch.3.033192","DOIUrl":"https://doi.org/10.1103/PhysRevResearch.3.033192","url":null,"abstract":"It is a well-established fact that the physical properties of compounds follow their crystal symmetries. This has especially pronounced implications on emergent collective quantum states in materials. Specifically, the effect of crystal symmetries on the properties of superconductors is widely appreciated, although the clarification of this relationship is a core effort of on-going research. Emergent phenomena on honeycomb lattices are of special interest, as they can give rise to spectacular phenomenology, as manifested by the recent discovery of correlated states in magic-angle graphene, or by the high-temperature superconductivity in MgB$_2$. Here, we report on the structural and microscopic superconducting properties of a class of ternary superconductors with Al/Si honeycomb layers, i.e. Ca$_{1-x}$Sr$_{x}$AlSi. We show that this solid solution is a remarkable model system with a highly tunable two-gap to single-gap superconducting system on a honeycomb lattice, where the superconductivity is enhanced by a subtle structural instability, i.e. the buckling of the Al/Si layers.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84183736","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

Boundary topological superconductors 边界拓扑超导体

arXiv: Superconductivity Pub Date : 2020-09-02 DOI: 10.1103/PHYSREVB.103.064512

Bo Li, Zhongbo Yan

{"title":"Boundary topological superconductors","authors":"Bo Li, Zhongbo Yan","doi":"10.1103/PHYSREVB.103.064512","DOIUrl":"https://doi.org/10.1103/PHYSREVB.103.064512","url":null,"abstract":"For strongly anisotropic time-reversal invariant (TRI) insulators in two and three dimensions, the band inversion can occur respectively at all TRI momenta of a high symmetry axis and plane. Although these classes of materials are topologically trivial as the strong and weak $Z_{2}$ indices are all trivial, they can host an even number of unprotected helical gapless edge states or surface Dirac cones on some boundaries. We show in this work that when the gapless boundary states are gapped by $s_{pm}$-wave superconductivity, a boundary time-reversal invariant topological superconductor (BTRITSC) characterized by a $Z_{2}$ invariant can be realized on the corresponding boundary. Since the dimension of the BTRITSC is lower than the bulk by one, the whole system is a second-order TRI topological superconductor. When the boundary of the BTRITSC is further cut open, Majorana Kramers pairs and helical gapless Majorana modes will respectively appear at the corners and hinges of the considered sample in two and three dimensions. Furthermore, a magnetic field can gap the helical Majorana hinge modes of the three-dimensional second-order TRI topological superconductor and lead to the realization of a third-order topological superconductor with Majorana corner modes. Our proposal can potentially be realized in insulator-superconductor heterostructures and iron-based superconductors whose normal states take the desired inverted band structures.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89511556","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: 6

Superconducting mechanism for the cuprate Ba2CuO3+δ based on a multiorbital Lieb lattice model 基于多轨道Lieb晶格模型的Ba2CuO3+δ铜的超导机理

arXiv: Superconductivity Pub Date : 2020-09-02 DOI: 10.1103/physrevresearch.2.033356

K. Yamazaki, M. Ochi, D. Ogura, K. Kuroki, H. Eisaki, S. Uchida, H. Aoki

引用次数: 9

Hidden anomalous Hall effect in Sr2RuO4 with chiral superconductivity dominated by the Ru dxy orbital Sr2RuO4中以Ru dxy轨道为主导的手性超导的隐藏异常霍尔效应

arXiv: Superconductivity Pub Date : 2020-08-31 DOI: 10.1103/physrevb.102.180509

Jia-Long Zhang, Yu Li, Wen Huang, Fu-Chun Zhang

{"title":"Hidden anomalous Hall effect in \u0000Sr2RuO4\u0000 with chiral superconductivity dominated by the Ru \u0000dxy\u0000 orbital","authors":"Jia-Long Zhang, Yu Li, Wen Huang, Fu-Chun Zhang","doi":"10.1103/physrevb.102.180509","DOIUrl":"https://doi.org/10.1103/physrevb.102.180509","url":null,"abstract":"The polar Kerr effect in superconducting Sr$_2$RuO$_4$ implies finite ac anomalous Hall conductivity. Since intrinsic anomalous Hall effect (AHE) is not expected for a chiral superconducting pairing developed on the single Ru $d_{xy}$ orbital, multiorbital chiral pairing actively involving the Ru $d_{xz}$ and $d_{yz}$ orbitals has been proposed as a potential mechanism. Here we propose that AHE could still arise even if the chiral superconductivity is predominantly driven by the $d_{xy}$ orbital. This is demonstrated through two separate models which take into account subdominant orbitals in the Cooper pairing, one involving the oxygen $p_x$ and $p_y$ orbitals in the RuO$_2$ plane, and another the $d_{xz}$ and $d_{yz}$ orbitals. In both models, finite orbital mixing between the dominant $d_{xy}$ and the other orbitals may induce inter-orbital pairing between them, and the resultant states support intrinsic AHE, with Kerr rotation angles that could potentially reconcile with the experimental observation. Our proposal therefore sheds new light on the microscopic pairing in Sr$_2$RuO$_4$. We also show that intrinsic Hall effect is generally absent for non-chiral states such as $mathcal{S}+imathcal{D}$, $mathcal{D}+imathcal{P}$ and $mathcal{D}+imathcal{G}$, which provides a clear constraint on the symmetry of the superconducting order in this material.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74393717","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: 5

Charge density waves beyond the Pauli paramagnetic limit in 2D systems 二维系统中超过泡利顺磁极限的电荷密度波

arXiv: Superconductivity Pub Date : 2020-08-28 DOI: 10.1063/5.0015993

A. Aperis, G. Varelogiannis

{"title":"Charge density waves beyond the Pauli paramagnetic limit in 2D systems","authors":"A. Aperis, G. Varelogiannis","doi":"10.1063/5.0015993","DOIUrl":"https://doi.org/10.1063/5.0015993","url":null,"abstract":"Two-dimensional materials are ideal candidates to host Charge density waves (CDWs) that exhibit paramagnetic limiting behavior, similarly to the well known case of superconductors. Here we study how CDWs in two-dimensional systems can survive beyond the Pauli limit when they are subjected to a strong magnetic field by developing a generalized mean-field theory of CDWs under Zeeman fields that includes incommensurability, imperfect nesting and temperature effects and the possibility of a competing or coexisting Spin density wave (SDW) order. Our numerical calculations yield rich phase diagrams with distinct high-field phases above the Pauli limiting field. For perfectly nested commensurate CDWs, a $q$-modulated CDW phase that is completely analogous to the superconducting Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase appears at high-fields. In the more common case of imperfect nesting, the commensurate CDW groundstate undergoes a series of magnetic-field-induced phase transitions first into a phase where commensurate CDW and SDW coexist and subsequently into another phase where CDW and SDW acquire a $q$-modulation that is however distinct from the pure FFLO CDW phase. The commensurate CDW+SDW phase occurs for fields comparable to but less than the Pauli limit and survives above it. Thus this phase provides a plausible mechanism for the CDW to survive at high fields without the need of forming the more fragile FFLO phase. We suggest that the recently discovered 2D materials like the transition metal dichalcogenides offer a promising platform for observing such exotic field induced CDW phenomena.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88716024","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

Unconventional Superconductivity Induced by Suppressing an Iron-Selenium-Based Mott Insulator CsFe4−xSe4 抑制铁硒基Mott绝缘体CsFe4−xSe4诱导的非常规超导性

arXiv: Superconductivity Pub Date : 2020-08-27 DOI: 10.1103/physrevx.10.041008

Jin Si, Guanyu Chen, Qing Li, Xiyu Zhu, Huan Yang, H. Wen

{"title":"Unconventional Superconductivity Induced by Suppressing an Iron-Selenium-Based Mott Insulator \u0000CsFe4−xSe4","authors":"Jin Si, Guanyu Chen, Qing Li, Xiyu Zhu, Huan Yang, H. Wen","doi":"10.1103/physrevx.10.041008","DOIUrl":"https://doi.org/10.1103/physrevx.10.041008","url":null,"abstract":"There are several FeSe based superconductors, including the bulk FeSe, monolayer FeSe thin film, intercalated KxFe2-ySe2 and Li1-xFexOHFeSe, etc. Their normal states all show metallic behavior. The key player here is the FeSe layer which exhibits the highest superconducting transition temperature in the form of monolayer thin film. Recently a new FeSe based compound, CsFe4-xSe4 with the space group of Bmmm was found. Interestingly the system shows a strong insulator-like behavior although it shares the same FeSe planes as other relatives. Density functional theory calculations indicate that it should be a metal, in sharp contrast with the experimental observations. Here we report the emergence of unconventional superconductivity by applying pressure to suppress this insulator-like behavior. At ambient pressure, the insulator-like behavior cannot be modeled as a band insulator, but can be described by the variable-range-hopping model for correlated systems. Furthermore, the specific heat down to 400 mK has been measured and a significant residual coefficient gamma_0=C/T|T->0 is observed, which contrasts the insulator-like state and suggests some quantum freedom of spin dynamics. By applying pressure the insulator-like behavior is gradually suppressed and the system becomes a metal, finally superconductivity is achieved at about 5.1 K. The superconducting transition strongly depends on magnetic field and applied current, indicating a fragile superfluid density. Our results suggest that the superconductivity is established by diluted Cooper pairs on top of a strong correlation background in CsFe4-xSe4.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84996976","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: 4

Double Majorana vortex zero modes in superconducting topological crystalline insulators with surface rotation anomaly 具有表面旋转异常的超导拓扑晶体绝缘体的双马约拉纳涡旋零模式

arXiv: Superconductivity Pub Date : 2020-08-25 DOI: 10.1103/physrevb.102.180505

S. Kobayashi, A. Furusaki

引用次数: 4