Tunable anomalous Andreev reflection and triplet pairings in spin-orbit-coupled graphene

Beiranvand, Reza; Hamzehpour, Hossein; Alidoust, Mohammad

doi:10.1103/physrevb.94.125415

Cited by 53 publications

(49 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Accordingly, the splitting of the ZBCP first strengthens and then weakens. Hence, the equal-spin triplet pairing states in this graphene-based d-wave SC junction are also controllable by tuning the Fermi levels, which is consistent with those of [30,31].…”

Section: Influence Of Tunable Chemical Potentialsupporting

confidence: 71%

“…The RSOC-induced spin-triplet AR occurs in the graphene-based FM/RSOC/s-wave SC junction, where the incident electrons and the reflected holes come from the same spin sub-band. This novel equal-spin AR results in nonvanishing superconducting triplet equal-spin pairings in the ferromagnetic region near the FM/RSO interface [30]. In most previous theoretical works on the spin-triplet pairing in graphene-based FM/ SC structures, the SC layer was assumed to be of s-wave [30][31][32].…”

Section: Introductionmentioning

confidence: 99%

“…This novel equal-spin AR results in nonvanishing superconducting triplet equal-spin pairings in the ferromagnetic region near the FM/RSO interface [30]. In most previous theoretical works on the spin-triplet pairing in graphene-based FM/ SC structures, the SC layer was assumed to be of s-wave [30][31][32]. However, the spin-triplet AR in the graphenebased d-wave SC junctions has not been studied so far.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Identifying the graphene d-wave superconducting symmetry by an anomalous splitting zero-bias conductance peak

et al. 2020

View full text Add to dashboard Cite

Not until recently, was a gate-tunable, high-temperature superconducting proximity effect in graphene demonstrated experimentally. And usually in d-wave superconductor (SC) hybrid structure, ferromagnetism and spin-triplet states could result in a splitting zero-bias conductance peak (ZBCP). Herein, we theoretically present an anomalous splitting ZBCP in a graphene-based ferromagnet/ Rashba spin-orbit coupling (RSOC)/insulator/d-wave SC hybrid structure. With increasing the exchange field from h/E F =0, the ZBCP starts to turn into a splitting one with a zero-bias conductance dip (ZBCD) sandwiched in between two subpeaks, while from h/E F =1, the two subpeaks and ZBCD begin to gradually shrink till the ZBCP reappears. The anomalous splitting ZBCP can be modulated by the RSOC strength, magnitude of Fermi wave vector mismatch as well as insulator barrier strength. These peculiar features are ascribed to the novel spin-triplet Andreev reflection in the context of the RSOC, characteristic by the anisotropic d-wave pair symmetry combined with the relativistic nodal fermions, which in turn can be experimentally used to directly identify not only the proximity-induced ferromagnetism and RSOC but d-wave pair symmetry in graphene. These results pave the way to a new class of tunable, high-temperature superconducting spintronic devices based on large-scale graphene.

show abstract

Section: Influence Of Tunable Chemical Potentialsupporting

confidence: 71%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Identifying the graphene d-wave superconducting symmetry by an anomalous splitting zero-bias conductance peak

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The band structure in the presence of RSOI is gap-less with a splitting of magnitude 2λ between two sub-bands in contrast to the intrinsic spin-orbit couplings. The sub-band splitting due to the RSOI results in very interesting phenomena [52][53][54].…”

Section: Model and Analysismentioning

confidence: 99%

Tunable magnetoresistance in spin-orbit coupled graphene junctions

Beiranvand

Hamzehpour

2019

Journal of Magnetism and Magnetic Materials

Self Cite

View full text Add to dashboard Cite

Using the Landauer-Bütikker formalism, we study the graphene magneto-transport in the presence of Rashba spin-orbit interaction (RSOI). we show that the angle resolved transmission probability in the proposed structures can be tuned by the RSOI strength. The transmission spectrum show Klein tunneling in the parallel (P) magnetization configuration which can be blocked by the RSOI. This effect is also observable for the anti-parallel (AP) magnetization configuration in different incident angle. The numerical results shows that the spin-polarized conductance strongly depends on the strength of the RSOI and can be generated by tuning the magnetic exchange field and RSOI strength. This spin-polarized conductance is a sensitive oscillatory function of the thickness of the RSO region. Because of the spin-flip effect, the junction shows a spin-valve effect with large and negative magnetoresistance (MR) and spin-magnetoresistance (SMR) in the presence of RSOI. When the RSOI is on, the frequency and amplitude of shot-noise and Fano factor's oscillations are also increased. These results can provide a way to extending the application of graphene-based junctions in spintronics. * razieh.beiranvand@abru.ac.ir arXiv:1808.03957v1 [cond-mat.mes-hall]

show abstract

“…Our implications for enhanced triplet pairing and MAAR detection could also be relevant for two-dimensional materials, as supported by the work in Refs. [48,49]. Another extension of this work could include the role of magnetic textures which themselves result in synthetic spin-orbit coupling and could be used to control Majorana bound states [50][51][52][53][54][55][56][57].…”

mentioning

confidence: 98%

Enhanced spin-triplet pairing in magnetic junctions with s -wave superconductors

et al. 2020

View full text Add to dashboard Cite

A common path to superconducting spintronics, Majorana fermions, and topologically-protected quantum computing relies on spin-triplet superconductivity. While naturally occurring spin-triplet pairing is elusive and even common spin-triplet candidates, such as Sr2RuO4, support alternative explanations, proximity effects in heterostructures can overcome these limitations. It is expected that robust spin-triplet superconductivity in magnetic junctions should rely on highly spin-polarized magnets or complex magnetic multilayers. Instead, we predict that the interplay of interfacial spin-orbit coupling and the barrier strength in simple magnetic junctions, with only a small spin polarization and s-wave superconductors, can lead to nearly complete spin-triplet superconducting proximity effects. This peculiar behavior arises from an effective perfect transparency: interfacial spin-orbit coupling counteracts the native potential barrier for states of a given spin and wave vector. We show that the enhanced spin-triplet regime is characterized by a huge increase in conductance magnetoanisotropy, orders of magnitude larger than in the normal state.

show abstract

Tunable anomalous Andreev reflection and triplet pairings in spin-orbit-coupled graphene

Cited by 53 publications

References 63 publications

Identifying the graphene d-wave superconducting symmetry by an anomalous splitting zero-bias conductance peak

Identifying the graphene d-wave superconducting symmetry by an anomalous splitting zero-bias conductance peak

Tunable magnetoresistance in spin-orbit coupled graphene junctions

Enhanced spin-triplet pairing in magnetic junctions with s -wave superconductors

Contact Info

Product

Resources

About