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Related papers: Quantum Spin Fluctuations as a Source of Long-Rang…

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Electron tunneling in ferromagnetic single-electron transistors is considered theoretically in the sequential tunneling regime. A new formalism is developed, which operates in a two-dimensional space of states, instead of one-dimensiona…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 J. Barnas , J. Martinek , G. Michalek , B. R. Bulka , A. Fert

We have observed reproducible fluctuations of the Coulomb drag, both as a function of magnetic field and electron concentration, which are a manifestation of quantum interference of electrons in the layers. At low temperatures the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 A. S. Price , A. K. Savchenko , B. N. Narozhny , G. Allison , D. A. Ritchie

The Andreev reflection probability for a ferromagnet/isolator/superconductor (FIS) contact at the arbitrary spin-dependent amplitudes of the electron waves transmitted through and reflected from the potential barrier is found. It is shown…

Superconductivity · Physics 2009-11-13 B. P. Vodopyanov

We study Andreev reflection in a ballistic one-dimensional channel coupled in parallel to a superconductor via a tunnel barrier of finite length $L$. The dependence of the low-energy Andreev reflection probability $R_A$ on $L$ reveals the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Giorgos Fagas , Grigory Tkachov , Andreas Pfund , Klaus Richter

The theory of spin fluctuations is developed for an ensemble of localized electrons taking into account both hyperfine interaction of electron and nuclear spins and electron hopping between the sites. The analytical expression for the spin…

Mesoscale and Nanoscale Physics · Physics 2015-05-07 M. M. Glazov

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

The paper considers the effects of random fluctuations of the local spin connectivities (fluctuations of the geometry) on ground state properties of a two-dimensional quantum antiferromagnet. We analyse the behavior of spins described by…

Strongly Correlated Electrons · Physics 2015-06-03 Anuradha Jagannathan , Benoit Douçot , Attila Szallas , Stefan Wessel

Applying the linearized Usadel equations, we consider the nucleation of superconductivity in multiply connected mesoscopic superconductor/ferromagnet (S/F) hybrids such as a thin superconducting ring on a ferromagnet with a uniform in-plane…

Superconductivity · Physics 2019-07-17 A. V. Samokhvalov , J. W. A. Robinson , A. I. Buzdin

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

Quantum fluctuations, through quantum corrections, have the potential to lead to irreversibility in quantum field theory. We consider the virtual ``charge" distribution generated by quantum corrections in the leading log, short range…

High Energy Physics - Theory · Physics 2007-05-23 J. Perez-Mercader

The very special characteristic of the proximity effect in superconductor-ferromagnet systems is the damped oscillatory behavior of the Cooper pair wave function in a ferromagnet. In some sense, this is analogous to the inhomogeneous…

Superconductivity · Physics 2009-11-11 A. I. Buzdin

We study a localized spin coupled to an Anderson impurity to model the situation found in higher transition metal or rare earth compounds like e.g.\ LaMnO$_3$ or Gd monopnictides. We find that, even for large quantum numbers of the…

Strongly Correlated Electrons · Physics 2007-05-23 Robert Peters , Thomas Pruschke

This work discusses theoretically the interplay between the superconducting and ferromagnetic proximity effects, in a diffusive normal metal strip in contact with a superconductor and a non-uniformly magnetized ferromagnetic insulator. The…

Superconductivity · Physics 2011-10-18 Audrey Cottet

We study Coulomb correlation effects and their role in superconductivity of $\varepsilon$-iron under pressure from 12 to 33 GPa by using a combination of density functional and dynamical mean-field theory. Our results indicate a persistence…

Strongly Correlated Electrons · Physics 2026-01-14 A. S. Belozerov , A. A. Katanin , V. Yu. Irkhin , V. I. Anisimov

Spin fluctuations have a substantial influence on the electron and lattice behaviors in magnetic materials, which, however, is difficult to be tracked properly by prevalent first-principles methods. We propose a versatile self-adaptive…

Materials Science · Physics 2023-02-14 Zefeng Cai , Ke Wang , Yong Xu , Su-Huai Wei , Ben Xu

We investigate the influence of itinerant carriers on dynamics and fluctuation of local moments in Fe-based superconductors, via linear spin-wave analysis of a spin-fermion model containing both itinerant and local degrees of freedom.…

Strongly Correlated Electrons · Physics 2015-09-14 Yu-Ting Tam , Dao-Xin Yao , Wei Ku

An incoming electron is reflected back as a hole at a normal-metal-superconductor interface, a process known as Andreev reflection. We predict that there exists a universal transverse shift in this process due to the effect of spin-orbit…

Mesoscale and Nanoscale Physics · Physics 2017-09-13 Ying Liu , Zhi-Ming Yu , Shengyuan A. Yang

The presence of a spin-flip potential at the interface between a superconductor and a ferromagnetic metal allows for the generation of equal-spin spin-triplet Cooper pairs. These Cooper pairs are compatible with the exchange interaction…

Superconductivity · Physics 2014-09-02 Daniel Fritsch , James F. Annett

A complete set of the generalized drift-diffusion equations for a coupled charge and spin dynamics in ferromagnets in the presence of extrinsic spin-orbit coupling is derived from the quantum kinetic approach, covering major transport…

Mesoscale and Nanoscale Physics · Physics 2018-05-02 C. O. Pauyac , M. Chshiev , A. Manchon , S. A. Nikolaev

It has been long suspected that spin fluctuations in the weak itinerant ferromagnet ZrZn2 may lead to a triplet superconductivity in this material. Here we point out another possibility, a spatially inhomogeneous singlet superconducting…

Superconductivity · Physics 2009-11-07 D. J. Singh , I. I. Mazin