Related papers: Andreev Reflections in NbN/graphene Junctions unde…
This is a colloquium-style introduction to two electronic processes in a carbon monolayer (graphene), each having an analogue in relativistic quantum mechanics. Both processes couple electron-like and hole-like states, through the action of…
Because the valleys in the band structure of graphene are related by time-reversal symmetry, electrons from one valley are reflected as holes from the other valley at the junction with a superconductor. We show how this Andreev reflection…
The transport properties of a ferromagnet-superconductor (FS) junction are studied in a scattering formulation. Andreev reflection at the FS interface is strongly affected by the exchange interaction in the ferromagnet. The conductance G_FS…
Using a wavefunction Dirac Bogoliubov-de Gennes method, we demonstrate that the tunable Fermi level of a graphene layer in the presence of Rashba spin orbit coupling (RSOC) allows for producing an anomalous nonlocal Andreev reflection and…
We perform a systematic study of Andreev conversion at the interface between a superconductor and graphene in the quantum Hall (QH) regime. We find that the probability of Andreev conversion from electrons to holes follows an unexpected but…
We have investigated transport through graphene Andreev interferometers exhibiting reentrance of the superconducting proximity effect. We observed a crossover in the Andreev conductance oscillations as a function of gate voltage ($V_{BG}$).…
Two-dimensional (2D) materials, composed of single atomic layers, have attracted vast research interest since the breakthrough discovery of graphene. One major benefit of such systems is the simple ability to tune the chemical potential by…
The quantum Hall (QH) effect supports a set of chiral edge states at the boundary of a 2-dimensional electron gas (2DEG) system. A superconductor (SC) contacting these states induces correlation of the quasi-particles in the dissipationless…
We numerically investigate Andreev reflection in a graphene ring with one normal conducting and one superconducting lead by solving the Bogoliubov--de Gennes equation within the Landauer-B\"uttiker formalism. By tuning chemical potential…
In view of the recent progress in experiments on charge transport through various Josephson junctions made out of graphene, we have made a careful comparison between the theory and some of the available experimental results. Within the…
Electrons can be reflected at an interface between two metals because of a dielectric barrier or different properties of the Fermi surface. Andreev reflection allows to directly measure normal reflection when one of the metals is a…
We study crossed Andreev reflection (CAR) of electrons or holes in normal metal-superconductor-normal metal junctions and highlight some very strong effects of the underlying lattice. In particular, we demonstrate that for sharp interfaces…
We study Andreev processes and nonlocal transport in a three-terminal graphene-superconductor hybrid system under a quantizing perpendicular magnetic field [G.-H. Lee et al., Nature Phys. 13, 693 (2017)]. We find that the amplitude of the…
Altermagnets are a new class of magnetic materials, which exhibit large spin splitting, but due to the combined spin and real space group symmetry protection maintain zero net macroscopic magnetization. Such a characteristic may prove them…
Shot noise cross-correlations across single layer graphene structures are calculated with insulators separating a superconducting region. A new feature of specular crossed Andreev reflection comes into play due to the unique band structure…
We consider a quantum Hall (QH) region in contact with a superconductor (SC), i.e., a QH-SC junction. Due to successive Andreev reflections, the QH-SC interface hosts hybridized electron and hole edge states called chiral Andreev edge…
We show that interface bound states are formed at isolated graphene-superconductor junctions. These states arise due to the interplay of virtual Andreev and normal reflections taking place at these interfaces. Simple analytical expressions…
We propose a new process of magnon-assisted Andreev reflection at a ferromagnetic metal - superconductor interface, which consists of the simultaneous injection of a Cooper pair from the superconductor and the emission of a magnon inside…
We study resonant tunneling through a superconducting double barrier structure in graphene as a function of the system parameters. At each barrier, due to the proximity effect, an incident electron can either reflect as an electron or a…
We study nonequilibrium Andreev resonances in a voltage-biased graphene three-terminal Josephson junction (JJ). We observe periodic oscillations of resistance with maxima at multiples of the magnetic flux quantum (noninversion regime). As…