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Related papers: Pure spin current in graphene NS structures

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Spin-polarized transport is investigated in normal metal-superconductor (NS) junctions as a function of interface transmissivity as well as temperature when the density of states of a superconductor is Zeeman-split in response to an…

Mesoscale and Nanoscale Physics · Physics 2008-04-03 F. Giazotto , F. Taddei

Graphene - a single atomic layer of graphite - is a recently-found two-dimensional form of carbon, which exhibits high crystal quality and ballistic electron transport at room temperature. Soft magnetic NiFe electrodes have been used to…

Mesoscale and Nanoscale Physics · Physics 2019-08-19 E. W. Hill , A. K. Geim , K. Novoselov , F. Schedin , P. Blake

We theoretically demonstrate the capability of a ferromagnetic-normal (FN) interface in graphene to focus an electron-wave with a certain spin direction. The essential feature is the negative refraction Klein tunneling, which is…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 Ali G. Moghaddam , Malek Zareyan

We construct high-quality graphene-based van der Waals devices with narrow superconducting niobium nitride (NbN) electrodes, in which superconductivity and robust fqH coexist. We find crossed Andreev reflection (CAR) across the…

One efficient mechanism for generating a charge supercurrent is Andreev reflection, in which the electric current injected from a normal metal into a conventional superconductor is converted into a supercurrent, thereby preserving charge…

Superconductivity · Physics 2026-03-31 Ping Li , Tao Yu

We study the crossed Andreev reflection and the nonlocal transport in the proximitized graphene/supercondcutor/proximitized graphene junctions with the pseudospin staggered potential and the intrinsic spin-orbit coupling. The crossed…

Superconductivity · Physics 2023-10-27 Shu-Chang Zhao , Lu Gao , Qiang Cheng , Qing-Feng Sun

Graphene's exceptional electronic mobility, gate-tunability, and contact transparency with superconducting materials make it ideal for exploring the superconducting proximity effect. However, the work function difference between graphene…

Mesoscale and Nanoscale Physics · Physics 2025-03-18 Seong Jang , Geon-Hyoung Park , Sein Park , Hyeon-Woo Jeong , Kenji Watanabe , Takashi Taniguchi , Gil-Ho Lee

We study the Andreev reflections and the quantum transport in the proximitized graphene/superconductor junction. The proximitized graphene possesses the pseudospin staggered potential and the intrinsic spin-orbit coupling induced by…

Mesoscale and Nanoscale Physics · Physics 2023-07-20 Lu Gao , Qiang Cheng , Qing-Feng Sun

We examine the appearance of a spontaneous bulk spin current in a triplet superconductor in contact with a metallic ferromagnet. The spin current results from the spin-flip of Cooper pairs upon reflection from the interface with the…

Superconductivity · Physics 2009-12-23 P. M. R. Brydon

We show a spin superconductor (SSC) in ferromagnetic graphene as the counterpart to the charge superconductor, in which a spin-polarized electron-hole pair plays the role of the spin $2 (\hbar/2)$ `Cooper pair' with a neutral charge. We…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 Qing-feng Sun , Zhao-tan Jiang , Yue Yu , X. C. Xie

We report the investigation of electron transport through a four-terminal graphene-superconductor hybrid system. Due to the quantum interference of the reflected holes from two graphene-superconductor interfaces with phase difference…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Shu-guang Cheng , Yanxia Xing , Jian Wang , Qing-feng Sun

Because of its fascinating electronic properties, graphene is expected to produce breakthroughs in many areas of nanoelectronics. For spintronics, its key advantage is the expected long spin lifetime, combined with its large electron…

We theoretically calculate the charge-supercurrent through a ballistic graphene junction where superconductivity is induced via the proximity-effect. Both monolayer and bilayer graphene are considered, including the possibility of strain in…

Superconductivity · Physics 2011-07-20 Mohammad Alidoust , Jacob Linder

A pure spin current is predicted to occur when an external magnetic field and a linearly inhomogeneous spin-only field are appropriately aligned. Under these conditions (such as originate from nuclear contact hyperfine fields that do not…

Mesoscale and Nanoscale Physics · Physics 2022-09-14 Nicholas J. Harmon , Michael E. Flatté

We demonstrate with a fully quantum-mechanical approach that graphene can function as gate-controllable transistors for pumped spin currents, i.e., a stream of angular momentum induced by the precession of adjacent magnetizations, which…

Mesoscale and Nanoscale Physics · Physics 2010-06-10 F. S. M. Guimarães , A. T. Costa , R. B. Muniz , M. S. Ferreira

Andreev reflection at a superconductor and Klein tunneling through an n-p junction in graphene are two processes that couple electrons to holes -- the former through the superconducting pair potential Delta and the latter through the…

Mesoscale and Nanoscale Physics · Physics 2013-07-09 C. W. J. Beenakker , A. R. Akhmerov , P. Recher , J. Tworzydlo

We show that spin-dependent electron-phonon interaction in the energy relaxation of a two-dimensional electron gas results in equal and oppositely directed currents in the spin-up and spin-down subbands yielding a pure spin current. In our…

Junctions composed of two crossed graphene nanoribbons (GNRs) have been theoretically proposed as electron beam splitters where incoming electron waves in one GNR can be split coherently into propagating waves in \emph{two} outgoing…

Mesoscale and Nanoscale Physics · Physics 2022-07-13 Sofia Sanz , Nick Papior , Géza Giedke , Daniel Sánchez-Portal , Mads Brandbyge , Thomas Frederiksen

Predictions are established for linear differential current-current cross-correlations dSab/dV in a symmetrically biased three-terminal normal metal-superconductor-normal metal (NSN) device. Highly transparent contacts turn out to be…

Superconductivity · Physics 2010-07-12 Axel Freyn , Martina Flöser , Régis Mélin

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