Manipulatable Andreev reflection due to the interplay between the DIII-class topological and s -wave superconductors

2018 ◽  
Vol 101 ◽  
pp. 278-283 ◽  
Author(s):  
Xiao-Qi Wang ◽  
Guang-Yu Yi ◽  
Yu Han ◽  
Cui Jiang ◽  
Wei-Jiang Gong
Keyword(s):  
Andreev Reflection ◽  
S Wave

Origin of the spin-triplet Andreev reflection at ferromagnet/s-wave superconductor interface

2008 ◽  
Vol 103 (2) ◽  
pp. 023921 ◽  
Author(s):  
Cui Di Feng ◽  
Zhi Ming Zheng ◽  
Yi Qun Ji ◽  
Zhi Ping Niu ◽  
D. Y. Xing
Keyword(s):  
Andreev Reflection ◽  
S Wave ◽  
Spin Triplet

scholarly journals P-wave Cooper pair splitting

2012 ◽  
Vol 3 ◽  
pp. 493-500 ◽  
Author(s):  
Henning Soller ◽  
Andreas Komnik
Keyword(s):  
Andreev Reflection ◽  
Cooper Pair ◽  
Hamiltonian Formalism ◽  
P Wave ◽  
Cooper Pairs ◽  
S Wave ◽  
Spin Singlet ◽  
Cross Correlations ◽  
On Chip ◽  
Crossed Andreev Reflection

Background: Splitting of Cooper pairs has recently been realized experimentally for s-wave Cooper pairs. A split Cooper pair represents an entangled two-electron pair state, which has possible application in on-chip quantum computation. Likewise the spin-activity of interfaces in nanoscale tunnel junctions has been investigated theoretically and experimentally in recent years. However, the possible implications of spin-active interfaces in Cooper pair splitters so far have not been investigated. Results: We analyze the current and the cross correlation of currents in a superconductor–ferromagnet beam splitter, including spin-active scattering. Using the Hamiltonian formalism, we calculate the cumulant-generating function of charge transfer. As a first step, we discuss characteristics of the conductance for crossed Andreev reflection in superconductor–ferromagnet beam splitters with s-wave and p-wave superconductors and no spin-active scattering. In a second step, we consider spin-active scattering and show how to realize p-wave splitting using only an s-wave superconductor, through the process of spin-flipped crossed Andreev reflection. We present results for the conductance and cross correlations. Conclusion: Spin-activity of interfaces in Cooper pair splitters allows for new features in ordinary s-wave Cooper pair splitters, that can otherwise only be realized by using p-wave superconductors. In particular, it provides access to Bell states that are different from the typical spin singlet state.

scholarly journals FIRST-PRINCIPLES CALCULATIONS OF SPIN-TRIPLET ANDREEV REFLECTION SPECTRA AT HALF-METALLIC FERROMAGNET/SUPERCONDUCTOR INTERFACE

2012 ◽  
Vol 26 (31) ◽  
pp. 1250205 ◽  
Author(s):  
LING TANG
Keyword(s):  
First Principles ◽  
Andreev Reflection ◽  
Magnetic Moments ◽  
S Wave ◽  
Interfacial Roughness ◽  
Zero Bias ◽  
Half Metallic ◽  
Magnetic Disorder ◽  
Spin Triplet ◽  
Metallic Ferromagnet

Combining the first-principles noncollinear calculations of scattering matrices with Andreev approximation, we investigated the spin-triplet Andreev reflection (AR) spectra for the interface between half-metallic ferromagnet Co 2 MnSi and s-wave BCS superconductor Al with and without interfacial roughness, where the orientations of magnetic moments near the interface are randomly distributed. The calculated results show that the AR spectra have peak structures near zero bias for the clean interface with relative weak magnetic disorder. With the increasing degree of interfacial roughness or magnetic disorder, these subgap peaks of conductance spectra will be washed out. The results also show that the value of subgap conductance spectrum can be raised significantly by the magnetic disorder. Finally, our calculations reveal that the long-range spin-triplet AR in Co 2 MnSi / Al (001) interface can be enhanced by a small amount of interfacial roughness.

scholarly journals Evidence for anisotropic spin-triplet Andreev reflection at the 2D van der Waals ferromagnet/superconductor interface

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ranran Cai ◽  
Yunyan Yao ◽  
Peng Lv ◽  
Yang Ma ◽  
Wenyu Xing ◽  
...  
Keyword(s):  
Bound States ◽  
Andreev Reflection ◽  
Van Der Waals ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Two Dimensional ◽  
S Wave ◽  
Fundamental Symmetry ◽  
Spin Triplet

AbstractFundamental symmetry breaking and relativistic spin–orbit coupling give rise to fascinating phenomena in quantum materials. Of particular interest are the interfaces between ferromagnets and common s-wave superconductors, where the emergent spin-orbit fields support elusive spin-triplet superconductivity, crucial for superconducting spintronics and topologically-protected Majorana bound states. Here, we report the observation of large magnetoresistances at the interface between a quasi-two-dimensional van der Waals ferromagnet Fe0.29TaS2 and a conventional s-wave superconductor NbN, which provides the possible experimental evidence for the spin-triplet Andreev reflection and induced spin-triplet superconductivity at ferromagnet/superconductor interface arising from Rashba spin-orbit coupling. The temperature, voltage, and interfacial barrier dependences of the magnetoresistance further support the induced spin-triplet superconductivity and spin-triplet Andreev reflection. This discovery, together with the impressive advances in two-dimensional van der Waals ferromagnets, opens an important opportunity to design and probe superconducting interfaces with exotic properties.

Spin-Triplet Andreev Reflection in Ferromagnet/Ferromangnet/ s -Wave Superconductor Junctions

2008 ◽  
Vol 25 (2) ◽  
pp. 691-693 ◽  
Author(s):  
Ji Yi-Qun ◽  
Niu Zhi-Ping ◽  
Feng Cui-Di ◽  
Xing Ding-Yu
Keyword(s):  
Andreev Reflection ◽  
S Wave ◽  
Spin Triplet

PULMONARY VASCULAR RESISTANCE BY ECHOCARDIOGRAPHY-DOPPLER IN ISCHEMIC HEART DISEASE WITH LEFT VENTRCULAR SYSTOLIC DYSFUNCTION

2017 ◽  
pp. 89-94
Author(s):  
Ke Toan Tran ◽  
Thi Thuy Hang Nguyen
Keyword(s):  
Heart Disease ◽  
Ischemic Heart Disease ◽  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Tricuspid Valve ◽  
Left Ventricular ◽  
Ischemic Heart ◽  
Left Ventricular Ejection ◽  
S Wave ◽  
Echocardiography Doppler

Objective: To determine pulmonary vascular resistance (PVR) by echocardiography - Doppler and to find correlation between pulmonary vascular resistance with left ventricular EF, PAPs, TAPSE, tissue S-wave of the tricuspid valve in patients with ischemic heart disease. Subjects and Methods: We studied on 82 patients with ischemic heart disease and EF<40% including 36 females, 46 males. Patients were estimated for pulmonary vascular resistance, EF, PAPs, TAPSE, tissue S-wave of the tricuspid valve by echocardiographyDoppler. Results: 64.6% of patients are increased PVR, average of PVR is 3.91 ± 1.85 Wood units and it is increasing with NYHA severity. There are negative correlations between pulmonary vascular resistance with left ventricular ejection fraction (r = - 0.545; p <0.001), TAPSE index (r= -0.590; p <0.001) and tissue S-wave of the tricuspid valve (r = -0.420; p <0.001); positive correlation with systolic pulmonary artery pressure (r = 0.361, p = 0.001), Conclusions: Increased PVR is the primary mechanism for pulmonary hypertension and right heart failure in patients with left heart disease. Determination of PVR in patients with left ventricular dysfunction by echocardiography is important in clinical practice. Key words: Echocardiography-Doppler; Pulmonary vascular resistance; ischemic heart disease

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