Formation of Fermi Arcs at T $$ \ll $$ Tc in the Vicinity of d-Wave Nodes of Structurally Inhomogeneous YBa2Cu3O6.92 HTSCs

2021 ◽  
Author(s):  
L. G. Mamsurova ◽  
N. G. Trusevich ◽  
L. I. Trakhtenberg
Keyword(s):  
Fermi Arcs ◽  
D Wave

scholarly journals Формирование Ферми-дуг при T<< T-=SUB=-c-=/SUB=- в окрестности d-волновых узлов структурно неоднородных ВТСП YBa-=SUB=-2-=/SUB=-Cu-=SUB=-3-=/SUB=-O-=SUB=-6.92-=/SUB=-

2021 ◽  
Vol 63 (8) ◽  
pp. 1040
Author(s):  
Л.Г. Мамсурова ◽  
Н.Г. Трусевич ◽  
Л.И. Трахтенберг
Keyword(s):  
Crystal Structure ◽  
Heat Capacity ◽  
Structural Disorder ◽  
Superconducting Gap ◽  
Ideal Crystal ◽  
High Tc Superconductors ◽  
High Tc ◽  
Fermi Arcs ◽  
Structural Disordering ◽  
D Wave

The effect of structural inhomogeneity on the superconducting gap near d-wave for optimally doped high-Tc superconductors YBa2Cu3O6.92 sites is considered. For this purpose, the heat capacity was investigated in the temperature range T = 2-10 K and in magnetic fields H = 0-9 T for a series of fine-crystalline samples with different degrees of controlled structural disordering. The information on the features of superconducting gap near d-wave sites in structurally disordered samples is obtained. It is shown that the d-wave sites inherent in an ideal crystal structure under the influence of structural disorder are modified with the formation of small Fermi arcs in the vicinity of nodal points at T << Tc, not covered by a superconducting gap. In this case, the gap itself remains at T ≤ Tc in other directions of the Brillouin zone and coexists with the Fermi arcs. This transformation is accompanied by an increase in the steepness of the nodal slope, a decrease of the Volovik effect, and the generation of a linear term γ (0) T of the metallic type in the temperature dependence of heat capacity, which should not be present in superconductors with an ideal crystal structure and the nature of which has not yet been established.

scholarly journals Holographic Fermi arcs and a d-wave gap

2011 ◽  
Vol 701 (5) ◽  
pp. 626-629 ◽  
Author(s):  
Francesco Benini ◽  
Christopher P. Herzog ◽  
Amos Yarom
Keyword(s):  
Fermi Arcs ◽  
D Wave

scholarly journals D wave bottomonia production from Zb(′) decay

2020 ◽  
Vol 102 (11) ◽  
Author(s):  
Qi Wu ◽  
Dian-Yong Chen ◽  
Takayuki Matsuki
Keyword(s):  
D Wave

scholarly journals Using Machine Learning for Quantum Annealing Accuracy Prediction

Algorithms ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 187
Author(s):  
Aaron Barbosa ◽  
Elijah Pelofske ◽  
Georg Hahn ◽  
Hristo N. Djidjev
Keyword(s):  
Machine Learning ◽  
Maximum Clique ◽  
Classification Model ◽  
Maximum Clique Problem ◽  
Problem Instance ◽  
Np Hard ◽  
Machine Learning Classification ◽  
Hard Problems ◽  
Problem Instances ◽  
D Wave

Quantum annealers, such as the device built by D-Wave Systems, Inc., offer a way to compute solutions of NP-hard problems that can be expressed in Ising or quadratic unconstrained binary optimization (QUBO) form. Although such solutions are typically of very high quality, problem instances are usually not solved to optimality due to imperfections of the current generations quantum annealers. In this contribution, we aim to understand some of the factors contributing to the hardness of a problem instance, and to use machine learning models to predict the accuracy of the D-Wave 2000Q annealer for solving specific problems. We focus on the maximum clique problem, a classic NP-hard problem with important applications in network analysis, bioinformatics, and computational chemistry. By training a machine learning classification model on basic problem characteristics such as the number of edges in the graph, or annealing parameters, such as the D-Wave’s chain strength, we are able to rank certain features in the order of their contribution to the solution hardness, and present a simple decision tree which allows to predict whether a problem will be solvable to optimality with the D-Wave 2000Q. We extend these results by training a machine learning regression model that predicts the clique size found by D-Wave.

scholarly journals Prediction of spin polarized Fermi arcs in quasiparticle interference in CeBi

2020 ◽  
Vol 102 (23) ◽  
Author(s):  
Zhao Huang ◽  
Christopher Lane ◽  
Chao Cao ◽  
Guo-Xiang Zhi ◽  
Yu Liu ◽  
...  
Keyword(s):  
Quasiparticle Interference ◽  
Fermi Arcs ◽  
Spin Polarized

d-wave superconductor as a model of high-Tcsuperconductors

1994 ◽  
Vol 49 (2) ◽  
pp. 1397-1402 ◽  
Author(s):  
Hyekyung Won ◽  
Kazumi Maki
Keyword(s):  
D Wave

scholarly journals Observation of a singular Weyl point surrounded by charged nodal walls in PtGa

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
J.-Z. Ma ◽  
Q.-S. Wu ◽  
M. Song ◽  
S.-N. Zhang ◽  
E. B. Guedes ◽  
...  
Keyword(s):  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Photoemission Spectroscopy ◽  
Functional Theory ◽  
Fermi Arc ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Fermi Arcs ◽  
Surface Projection ◽  
Applicable Range ◽  
Opposite Chirality

AbstractConstrained by the Nielsen-Ninomiya no-go theorem, in all so-far experimentally determined Weyl semimetals (WSMs) the Weyl points (WPs) always appear in pairs in the momentum space with no exception. As a consequence, Fermi arcs occur on surfaces which connect the projections of the WPs with opposite chiral charges. However, this situation can be circumvented in the case of unpaired WP, without relevant surface Fermi arc connecting its surface projection, appearing singularly, while its Berry curvature field is absorbed by nontrivial charged nodal walls. Here, combining angle-resolved photoemission spectroscopy with density functional theory calculations, we show experimentally that a singular Weyl point emerges in PtGa at the center of the Brillouin zone (BZ), which is surrounded by closed Weyl nodal walls located at the BZ boundaries and there is no Fermi arc connecting its surface projection. Our results reveal that nontrivial band crossings of different dimensionalities can emerge concomitantly in condensed matter, while their coexistence ensures the net topological charge of different dimensional topological objects to be zero. Our observation extends the applicable range of the original Nielsen-Ninomiya no-go theorem which was derived from zero dimensional paired WPs with opposite chirality.

Sign in / Sign up

Export Citation Format

Share Document