English
Related papers

Related papers: Andreev reflections at large ferromagnet/high-T_C …

200 papers

A Josephson junction, formed between two phase-biased superconductors and a normal metal, hosts a discrete spectrum of Andreev bound states (ABS). In this paper, we develop a theory for long ballistic Andreev interferometers in…

Mesoscale and Nanoscale Physics · Physics 2025-01-15 Régis Mélin , Asmaul Smitha Rashid , Morteza Kayyalha

Novel fermions with a pseudospin-1 structure can be realized as emergent quasiparticles in condensed matter systems. Here, we investigate its unusual properties during the Andreev reflection at a normal-metal/superconductor (NS) interface.…

Mesoscale and Nanoscale Physics · Physics 2020-07-01 Xiaolong Feng , Ying Liu , Zhi-Ming Yu , Zhongshui Ma , L. K. Ang , Yee Sin Ang , Shengyuan A. Yang

Scattering processes in quantum materials emerge as resonances in electronic transport, including confined modes, Andreev states, and Yu-Shiba-Rusinov states. However, in most instances, these resonances are driven by a single scattering…

Superconductivity · Physics 2023-04-26 Sharadh Jois , Jose L. Lado , Genda Gu , Qiang Li. , Ji Ung Lee

We study Andreev reflection in a normal conductor-molecule-superconductor junction using a first principles approach. In particular, we focus on a family of molecules consisting of a molecular backbone and a weakly coupled side group. We…

Mesoscale and Nanoscale Physics · Physics 2016-01-20 A. Kormanyos , I. Grace , C. J. Lambert

Coherent charge transport along ballistic paths can be introduced into graphene by Andreev reflection, for which an electron reflects from a superconducting contact as a hole, while a Cooper pair is transmitted. We use a liquid-helium…

Mesoscale and Nanoscale Physics · Physics 2020-08-26 S. Bhandari , G. -H. Lee , K. Watanabe , T. Taniguchi , P. Kim , R. M. Westervelt

Andreev-reflection dominated transport is demonstrated in Al/n-In0.38Ga0.62As superconductor-semiconductor junctions grown by molecular beam epitaxy on GaAs(001). High junction transparency was achieved in low-doped devices by exploiting Si…

Peaks associated to multiple Andreev reflections have been used to identify the number of conduction channels, and their transmitivity in mesoscopic superconducting junctions. We analyze the influence of the detailed shape of each channel,…

Superconductivity · Physics 2007-05-23 Elena Bascones , Francisco Guinea

The Andreev current and the subgap conductance in a superconductor/ insulator/ ferromagnet (SIF) structure in the presence of a small spin-splitting field show novel interesting features (A. Ozaeta et al., Phys. Rev. B 86, 060509(R), 2012).…

Superconductivity · Physics 2013-05-16 A. S. Vasenko , A. Ozaeta , S. Kawabata , F. W. J. Hekking , F. S. Bergeret

Very high applied pressure induces superconductivity with the transition temperature ($T_c$) exceeding 19 K in elemental yttrium, but relatively little is known about the nature of that superconductivity. From point-contact spectroscopy…

We investigate the applicability of spin polarization measurements using Andreev reflection in a point contact geometry in heavily doped dilute magnetic semiconductors, such as (Ga,Mn)As. While we observe conventional Andreev reflection in…

Strongly Correlated Electrons · Physics 2009-11-11 R. P. Panguluri , K. C. Ku , T. Wojtowicz , X. Liu , J. K. Furdyna , Y. B. Lyanda-Geller , N. Samarth , B. Nadgorny

Measurements of the differential conductance spectra of YBa2Cu3O7-SrRuO3 and YBa2Cu3O7-La0.67Ca_0.33MnO3 ramp-type junctions along the node and anti-node directions are reported. The results are consistent with a crossed Andreev reflection…

Superconductivity · Physics 2010-10-08 T. Kirzhner , G. Koren

The problem of Andreev reflection between a normal metal and a multiband superconductor is addressed. The appropriate matching conditions for the wave function at the interface are established on the basis of an extension of quantum…

Superconductivity · Physics 2009-05-29 M. A. N. Araujo , P. D. Sacramento

A normal conductor placed in good contact with a superconductor can inherit its remarkable electronic properties. This proximity effect microscopically originates from the formation in the conductor of entangled electron-hole states, called…

Mesoscale and Nanoscale Physics · Physics 2017-09-13 Landry Bretheau , Joel I-Jan Wang , Riccardo Pisoni , Kenji Watanabe , Takashi Taniguchi , Pablo Jarillo-Herrero

We investigate odd-frequency superconducting correlations in normal-superconductor (NS) and short superconductor-normal-superconductor (SNS) junctions with the S region described by the Kitaev model of spinless fermions in one dimension. We…

Mesoscale and Nanoscale Physics · Physics 2019-09-26 Athanasios Tsintzis , Annica M. Black-Schaffer , Jorge Cayao

Using the tight binding model and the non-equilibrium Green function method, we study Andreev reflection in graphene-superconductor junction, where graphene has two nonequal Dirac Cones split in energy and therefore time reversal symmetry…

Superconductivity · Physics 2020-01-15 Chao Wang , Lin Zhang , Peipei Zhang , Juntao Song , Yu-Xian Li

We investigate electron transport through the interface between a niobium superconductor and the edge of a two-dimensional semimetal, realized in a 20~nm wide HgTe quantum well. Experimentally, we observe that typical behavior of a single…

Mesoscale and Nanoscale Physics · Physics 2016-02-03 A. Kononov , S. V. Egorov , Z. D. Kvon , N. N. Mikhailov , S. A. Dvoretsky , E. V. Deviatov

By combining the Dirac equation of relativistic quantum mechanics with the Bogoliubov-De Gennes equation of superconductivity we investigate the electron-hole conversion at a normal-metal--superconductor interface in graphene. We find that…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 C. W. J. Beenakker

Point-contact Andreev-reflection measurements were performed in SmFeAsO_{0.8}F_{0.2} polycrystals with T_c \simeq 53 K. The experimental conductance curves reproducibly exhibit peaks around \pm 6 mV and shoulders at V \sim 16-20 mV,…

Superconductivity · Physics 2011-10-13 D. Daghero , M. Tortello , R. S. Gonnelli , V. A. Stepanov , N. D. Zhigadlo , J. Karpinski

We have measured the electrical transport of submicron ferromagnets (Ni) in contact with a mesoscopic superconductor (Al) for a range of interface resistances. In the geometry measured, the interface and the ferromagnet are measured…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 J. Aumentado , V. Chandrasekhar

Andreev-reflection spectroscopy of elemental superconductors in contact with non-magnetic normal metals reveals that the strength of normal-reflection varies only slightly. This observation imposes strong constrictions on the three possible…

Mesoscale and Nanoscale Physics · Physics 2015-06-22 K. Gloos , E. Tuuli