arXiv: Superconductivity最新文献_第8页

Effect of on-site Coulomb repulsion on ferromagnetic fluctuations in heavily over-doped cuprates. 现场库仑斥力对重掺杂铜酸盐铁磁波动的影响。

arXiv: Superconductivity Pub Date : 2020-08-21 DOI: 10.7566/JPSJ.90.094707

Shingo Teranishi, Kazutaka Nishiguchi, S. Yunoki, K. Kusakabe

引用次数: 5

Second Chern Number and Non-Abelian Berry Phase in Topological Superconducting Systems 拓扑超导系统中的第二陈氏数与非阿贝尔贝里相

arXiv: Superconductivity Pub Date : 2020-08-19 DOI: 10.1103/PRXQUANTUM.2.010310

Hannes Weisbrich, Raffael L. Klees, G. Rastelli, W. Belzig

引用次数: 25

Role of rare events in the pinning problem 罕见事件在钉住问题中的作用

arXiv: Superconductivity Pub Date : 2020-08-18 DOI: 10.1103/physrevresearch.2.043266

M. Buchacek, V. Geshkenbein, G. Blatter

{"title":"Role of rare events in the pinning problem","authors":"M. Buchacek, V. Geshkenbein, G. Blatter","doi":"10.1103/physrevresearch.2.043266","DOIUrl":"https://doi.org/10.1103/physrevresearch.2.043266","url":null,"abstract":"Type II superconductors exhibit a fascinating phenomenology that is determined by the dynamical properties of the vortex matter hosted by the material. A crucial element in this phenomenology is vortex pinning by material defects, e.g., immobilizing vortices at small drives and thereby guaranteeing dissipation-free current flow. Pinning models for vortices and other topological defects, such as domain walls in magnets or dislocations in crystals, come in two standard variants: i) weak collective pinning, where individual weak defects are unable to pin, while the random accumulation of many force centers within a collective pinning volume combines into an effective pin, and ii) strong pinning, where strong defects produce large vortex displacements and bistabilities that lead to pinning on the level of individual defects. The transition between strong and weak pinning is quantified by the Labusch criterion $kappa approx f_p/bar{C}xi = 1$, where $f_p$ and $bar{C}$ are the force of one defect and the effective elasticity of the vortex lattice, respectively ($xi$ is the coherence length). Here, we show that a third generic type of pinning becomes dominant when the pinning force $f_p$ enters the weak regime, the pinning by rare events. We find that within an intermediate regime $1/2 < kappa < 1$, compact pairs of weak defects define strong pinning clusters that extend the mechanism of strong pinning into the weak regime. We present a detailed analysis of this cluster-pinning mechanism and show that its pinning-force density parametrically dominates over the weak pinning result. The present work is a first attempt to include correlations between defects into the discussion of strong pinning.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81372053","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

Topological transitions in electronic spectra: Crossover between Abrikosov and Josephson vortices 电子谱中的拓扑跃迁:Abrikosov和Josephson涡旋之间的交叉

arXiv: Superconductivity Pub Date : 2020-08-17 DOI: 10.1103/physrevb.102.174501

A. Samokhvalov, V. Plastovets, A. S. M. I. F. P. O. Microstructures, R. A. O. Sciences, 603950 Nizhny Novgorod, GSP-105, Russia, Lobachevsky State University of Nizhni Novgorod, 603950 Nizhni Novgorod, Sirius University of Science, Technology, 1. O. Ave, 354340 Sochi

引用次数: 4

Materials preparation, single-crystal growth, and the phase diagram of the cuprate high-temperature superconductor La1.6−xNd0.4SrxCuO4 铜高温超导体La1.6−xNd0.4SrxCuO4的材料制备、单晶生长及相图

arXiv: Superconductivity Pub Date : 2020-08-17 DOI: 10.1103/PHYSREVMATERIALS.4.114801

Mirela Dragomir, Qianli Ma, J. Clancy, A. Ataei, P. Dube, Sudarshan Sharma, A. Huq, H. Da̧bkowska, L. Taillefer, D. Bruce, Gaulin

{"title":"Materials preparation, single-crystal growth, and the phase diagram of the cuprate high-temperature superconductor \u0000La1.6−xNd0.4SrxCuO4","authors":"Mirela Dragomir, Qianli Ma, J. Clancy, A. Ataei, P. Dube, Sudarshan Sharma, A. Huq, H. Da̧bkowska, L. Taillefer, D. Bruce, Gaulin","doi":"10.1103/PHYSREVMATERIALS.4.114801","DOIUrl":"https://doi.org/10.1103/PHYSREVMATERIALS.4.114801","url":null,"abstract":"One branch of the La-214 family of cuprate superconductors, La1.6-xNd0.4SrxCuO4 (Nd-LSCO), has been of significant and sustained interest, in large part because it displays the full complexity of the phase diagram for canonical hole-doped, high Tc superconductivity, while also displaying relatively low superconducting critical temperatures. The low superconducting Tc's imply that experimentally accessible magnetic fields can suppress the superconductivity to zero temperature. In particular, this has enabled various transport and thermodynamic studies of the T = 0 ground state in Nd-LSCO, free of superconductivity, across the critical doping p* = 0.23 where the pseudogap phase ends. The strong dependence of its superconducting properties on its crystal symmetry has itself motivated careful studies of the Nd-LSCO structural phase diagram. This paper provides a systematic study and summary of the materials preparation and characterization of both single crystal and polycrystalline samples of Nd-LSCO. Single-phase polycrystalline samples with x spanning the range from 0.01 to 0.40 have been synthesized, and large single crystals of Nd-LSCO for select x across the region (0.07, 0.12, 0.17, 0.19, 0.225, 0.24, and 0.26) were grown by the optical floating zone method. Systematic neutron and X-ray diffraction studies on these samples were performed at both low and room temperatures, 10 K and 300 K, respectively. These studies allowed us to follow the various structural phase transitions and propose an updated structural phase diagram for Nd-LSCO. In particular, we found that the low-temperature tetragonal (LTT) phase ends at a critical doping pLTT = 0.255(5), clearly separated from p*.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88507034","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: 12

Large enhancement of spin pumping due to the surface bound states in normal metal–superconductor structures 在正常的金属超导体结构中，由于表面束缚态，自旋泵浦大增强

arXiv: Superconductivity Pub Date : 2020-08-14 DOI: 10.1103/physrevb.102.180502

M. Silaev

引用次数: 13

Post-growth annealing effects on charge and spin excitations in Nd2−xCexCuO4 生长后退火对Nd2−xCexCuO4中电荷和自旋激发的影响

arXiv: Superconductivity Pub Date : 2020-08-08 DOI: 10.1103/PHYSREVMATERIALS.5.024803

K. Ishii, S. Asano, Masumi Ashida, M. Fujita, Biqiong Yu, M. Greven, J. Okamoto, D. Huang, J. Mizuki

引用次数: 4

Conductivity of superconductors in the flux flow regime 超导体在通量流动状态下的电导率

arXiv: Superconductivity Pub Date : 2020-08-07 DOI: 10.1103/physrevb.102.180507

M. Smith, A. Andreev, M. V. Feigel’man, B. Spivak

引用次数: 3

Ab initio simulation of non-Abelian braiding statistics in topological superconductors 拓扑超导体中非阿贝尔编织统计的从头算模拟

arXiv: Superconductivity Pub Date : 2020-08-07 DOI: 10.1103/PHYSREVB.103.054504

Takumi Sanno, Shunsuke Miyazaki, T. Mizushima, S. Fujimoto

{"title":"Ab initio\u0000 simulation of non-Abelian braiding statistics in topological superconductors","authors":"Takumi Sanno, Shunsuke Miyazaki, T. Mizushima, S. Fujimoto","doi":"10.1103/PHYSREVB.103.054504","DOIUrl":"https://doi.org/10.1103/PHYSREVB.103.054504","url":null,"abstract":"We numerically investigate non-Abelian braiding dynamics of vortices in two-dimensional topological superconductors, such as $s$-wave superconductors with Rashba spin-orbit coupling. Majorana zero modes (MZMs) hosted by the vortices constitute a topological qubit, which offers a fundamental building block of topological quantum computation. As the MZMs are protected by $mathbb{Z}_2$ invariant, however, the Majorana qubit and quantum gate operations may be sensitive to intrinsic decoherence caused by quasiparticle interference. Numerically simulating the time-dependent Bogoliubov-de Gennes equation without assuming ${it a priori}$ existence of MZMs, we examine quantum noises on the unitary operators of non-abelian braiding dynamics due to interactions with neighboring MZMs and other quasiparticle states. We demonstrate that after the interchange of two vortices, the lowest vortex-bound states accumulate the geometric phase $pi/2$, and errors stemming from dynamical phases are negligibly small, irrespective of interactions of MZMs. Furthermore, we numerically simulate the braiding dynamics of four vortices in two-dimensional topological superconductors, and discuss an optimal braiding condition for realizing the high performance of non-Abelian statistics and quantum gates operations of Majorana-based qubits.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86103936","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

Analysis of the ghost and mirror fields in the Nernst signal induced by superconducting fluctuations 超导涨落引起的能思特信号中的鬼场和镜场分析

arXiv: Superconductivity Pub Date : 2020-07-31 DOI: 10.1103/physrevb.102.174507

A. Glatz, A. Pourret, A. Varlamov

{"title":"Analysis of the ghost and mirror fields in the Nernst signal induced by superconducting fluctuations","authors":"A. Glatz, A. Pourret, A. Varlamov","doi":"10.1103/physrevb.102.174507","DOIUrl":"https://doi.org/10.1103/physrevb.102.174507","url":null,"abstract":"We present a complete analysis of the Nernst signal due to superconducting fluctuations in a large variety of superconductors from conventional to unconventional ones. A closed analytical expression of the fluctuation contribution to the Nernst signal is obtained in a large range of temperature and magnetic field. We apply this expression directly to experimental measurements of the Nernst signal in Nb$_x$Si$_{1-x}$ thin films and a URu$_2$Si$_2$ superconductors. Both magnetic field and temperature dependence of the available data are fitted with very good accuracy using only two fitting parameters, the superconducting temperature $T_{mathrm{c0}}$ and the upper critical field $H_{mathrm{c2}}$. The obtained values agree very well with experimentally obtained values. We also extract the ghost lines (maximum of the Nernst signal for constant temperature or magnetic field) from the complete expression and also compare it to several experimentally obtained curves. Our approach predicts a linear temperature dependence for the ghost critical field well above $T_{mathrm{c0}}$. Within the errors of the experimental data, this linearity is indeed observed in many superconductors far from $T_{mathrm{c0}}$.","PeriodicalId":8514,"journal":{"name":"arXiv: Superconductivity","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91260301","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: 0