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Andreev reflection (AR) in ferromagnet/superconductor junctions is an indispensable spectroscopic tool for measuring spin polarization. We study theoretically how the presence of a thin semiconducting interface in such junctions, inducing…

Superconductivity · Physics 2019-09-11 Andreas Costa , Alex Matos-Abiague , Jaroslav Fabian

We present a study of the Andreev reflections in superconductor/ferromagnet nanostructured point contacts. The experimental data are analyzed in the frame of a model with two spin-dependent transmission coefficients for the majority and…

Superconductivity · Physics 2009-11-10 F. Perez-Willard , J. C. Cuevas , C. Suergers , P. Pfundstein , J. Kopu , M. Eschrig , H. v. Loehneysen

We present a study of the superconducting energy gap performed with point contact spectroscopy in a single crystal of the superconductor Zr0:97V0:03B2. We determined the size and evolution with temperature of the energy gap, the transition…

Superconductivity · Physics 2015-06-01 Rodolfo E. López-Romero , R. Escudero

We study the Andreev and normal reflection processes -- retro as well as specular -- in a bilayer graphene-superconductor junction where equal and opposite displacement fields are applied for the top and bottom layers to induce a band gap.…

Superconductivity · Physics 2023-11-17 Panch Ram , Detlef Beckmann , Romain Danneau , Wolfgang Belzig

When a quantum dot is attached to a metallic reservoir and a superconducting contact Andreev processes leads to a finite subgap current at the normal lead and the creation or destruction of Cooper pairs. Andreev-reflection engines profit…

Mesoscale and Nanoscale Physics · Physics 2023-11-07 Gonzalo Manzano , Rosa López

The two-band/two-gap superconductivity in aluminium and carbon doped MgB$_2$ has been addressed by the point-contact spectroscopy. Two gaps are preserved in all samples with $T_c's$ down to 22 K. The evolution of two gaps as a function of…

Superconductivity · Physics 2015-06-25 P. Szabo , P. Samuely , Z. Hol'anova , S. Bud'ko , P. C. Canfield , J. Marcus

Epitaxially grown, high quality semiconductor InSb nanowires are emerging material systems for the development of high performance nanoelectronics and quantum information processing and communication devices, and for the studies of new…

Mesoscale and Nanoscale Physics · Physics 2012-04-19 H. A. Nilsson , P. Samuelsson , P. Caroff , H. Q. Xu

Point contacts (PC) Andreev reflection dV/dI spectra for the antiferromagnetic (T_N =6K) superconductor (Tc=11K) ErNi2B2C have been measured for the two main crystallographic directions. Observed retention of the Andreev reflection minima…

We study Andreev reflection in graphene nanoribbon/superconductor hybrid junctions. By using a tight-binding approach and the scattering formalism we show that finite-size effects lead to notable differences with respect to the bulk…

Mesoscale and Nanoscale Physics · Physics 2009-03-28 Diego Rainis , Fabio Taddei , Fabrizio Dolcini , Marco Polini , Rosario Fazio

We present a systematic analysis of point-contact Andreev reflection (PCAR) spectra for ferromagnetic materials, using both modeling and experimental data. We consider the relationship between ballistic and diffusive transport, the effect…

Strongly Correlated Electrons · Physics 2009-11-10 G. T. Woods , R. J. Soulen , I. I. Mazin. , B. Nadgorny , M. S. Osofsky , J. Sanders , H. Srikanth , W. F. Egelhoff , R. Datla

Particle transport across Josephson junctions is commonly described using a simplifying approximation (often called the Andreev approximation), which assumes that excitations are fixed at the Fermi momentum and only Andreev reflections,…

Mesoscale and Nanoscale Physics · Physics 2022-11-09 F. Setiawan , Johannes Hofmann

Electronic properties of mesoscopic systems made of normal metal in contact with normal and superconducting reservoirs are determined by Andreev Reflection. We address both experimentally and theoretically how Andreev Reflection manifests…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 B. Reulet , D. E. Prober , W. Belzig

We consider a hybrid system consisting of two normal metal leads weakly connected to a superconductor. Current-current correlations of the normal leads are studied in the tunneling limit at subgap voltages and temperatures. We find that…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 G. Bignon , M. Houzet , F. Pistolesi , F. W. J. Hekking

Andreev reflection occurs in a normal metal-superconductor junction, when an electron on the normal side can only be transmitted as a Cooper pair in the superconductor, with the reflection of a hole on the normal side. A similar phenomenon…

Mesoscale and Nanoscale Physics · Physics 2026-05-22 K. Iyer , T. Martin , J. Rech , T. Jonckheere

We study the Andreev reflection (AR) in a three terminal mesoscopic hybrid system, in which two ferromagnets (F$_1$ and F$_2$) are coupled to a superconductor (S) through a quantum dot (QD). By using non-equilibrium Green function, we…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Yu Zhu , Qing-feng Sun , Tsung-han Lin

We have observed that the supercurrent across phase-biased, highly transmitting atomic size contacts is strongly reduced within a broad phase interval around {\pi}. We attribute this effect to quasiparticle trapping in one of the discrete…

Mesoscale and Nanoscale Physics · Physics 2015-03-19 M. Zgirski , L. Bretheau , Q. Le Masne , H. Pothier , D. Esteve , C. Urbina

We analyze the dynamical Coulomb blockade of multiple Andreev reflections (MAR) in a superconducting quantum point contact coupled to a macroscopic impedance. We find that at very low transmission the blockade scales as $n^2$ with $n =…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 A. Levy Yeyati , J. C. Cuevas , A. Martin-Rodero

Andreev reflection spectroscopy with unpolarized and highly spin-polarized currents has been utilized to study an intermetallic single-crystal superconductor NiBi3. Magnetoresistance at zero bias voltage of point contacts shows the…

Superconductivity · Physics 2018-10-29 G. J. Zhao , X. X. Gong , P. C. Xu , B. C. Li , Z. Y. Huang , X F. Jin , X. D. Zhu , T. Y. Chen

We present a theory of the current-voltage characteristics in diffusive superconductor-normal-metal-superconductor junctions. By solving the time-dependent Usadel equations we are able to describe the phase-coherent transport for arbitrary…

Superconductivity · Physics 2009-11-11 J. C. Cuevas , J. Hammer , J. Kopu , J. K. Viljas , M. Eschrig

We theoretically propose the laser-induced Andreev reflection between two-component Fermi superfluid and normal states via spatially-uniform Rabi couplings. By analyzing the tunneling current between the superfluid and normal states up to…

Quantum Gases · Physics 2023-05-01 Tingyu Zhang , Hiroyuki Tajima , Yuta Sekino , Shun Uchino , Haozhao Liang