Transport in ferromagnet/superconductor spin valves

Moen, Evan; Valls, Oriol T.

doi:10.1103/physrevb.95.054503

Cited by 16 publications

(46 citation statements)

References 54 publications

(93 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Thus we can verify the relation between the STT and the spin current in Eq. (7), as has previously been pointed out 14,39 .…”

Section: B Spin Transport Quantitiessupporting

confidence: 71%

“…The transport properties are quite different for an applied voltage bias below and above the CB. This effect is also dependent on the misalignment angle of the exchange fields, usually in a nonmonotonic 39 way. Here, we examine the dependence of the spin-transport properties on the layer thicknesses, the importance of which has been mentioned above, the interfacial scattering strengths, and the applied bias voltage, including CB effects.…”

Section: Introductionmentioning

confidence: 99%

“…In our calculations, we use a self consistent solution to the Bogoliubov de Gennes (BdG) equations 51 to calculate the pair potential, and then employ this potential in the transport calculations via a transfer matrix method 39 . This method correctly incorporates the normal and Andreev reflection and transmission amplitudes of the electrons and holes.…”

Section: Introductionmentioning

confidence: 99%

“…We thus see a nonmonotonic dependence on φ, as well as a strong dependence on the interfacial scattering strengths. Interfacial scattering generally inhibits the proximity effects but, because there are several barriers, resonance features such as those found for charge transport 39 can also arise. We will also analyze the average of the spin transport quantities over each layer: we have found this particularly useful in studying the bias dependencies and in better establishing the underlying physical principles at work.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Spin current and spin transfer torque in ferromagnet/superconductor spin valves

Moen

Valls

2018

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

Using fully self consistent methods, we study spin transport in realistic, fabricable experimental spin valve systems consisting of two magnetic layers, a superconducting layer, and a spacer normal layer between the ferromagnets. Our methods ensure that the proper relations between spin current gradients and spin transfer torques are satisfied. We present results as a function of geometrical parameters, interfacial barrier values, misalignment angle between the ferromagnets, and bias voltage. Our main results are for the spin current and spin accumulation as functions of position within the spin valve structure. We see precession of the spin current about the exchange fields within the ferromagnets, and penetration of the spin current into the superconductor for biases greater than the critical bias, defined in the text. The spin accumulation exhibits oscillating behavior in the normal metal, with a strong dependence on the physical parameters both as to the structure and formation of the peaks. We also study the bias dependence of the spatially averaged spin transfer torque and spin accumulation. We examine the critical bias effect of these quantities, and their dependence on the physical parameters. Our results are predictive of the outcome of future experiments, as they take into account imperfect interfaces and a realistic geometry.

show abstract

“…Thus we can verify the relation between the STT and the spin current in Eq. (7), as has previously been pointed out 14,39 .…”

Section: B Spin Transport Quantitiessupporting

confidence: 71%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Spin current and spin transfer torque in ferromagnet/superconductor spin valves

Moen

Valls

2018

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

show abstract

“…In our argument, we are looking for a possible relationship between the observed transition temperature difference ∆T c and the current applied I dc in the transverse direction within the superconductor. From our transport calculations [42,43], we have found that the relative conductance, calculated for a longitudinal current between P and AP states can shift abruptly near the critical bias. We also have demonstrated [44] that this phenomenon arises from the marked difference between conductances in the up and down spin channels, which interact differently with the aligned or misaligned magnetizations.…”

Section: Discussion and Interpretationmentioning

confidence: 99%

Bias current dependence of superconducting transition temperature in superconducting spin-valve nanowires

2019

Self Cite

View full text Add to dashboard Cite

Competition between superconducting and ferromagnetic ordering at interfaces between ferromagnets (F) and superconductors (S) gives rise to several proximity effects such as odd-triplet superconductivity and spin-polarized supercurrents. A prominent example of an S/F proximity effect is the spin switch effect (SSE) observed in S/F/N/F superconducting spin valve multilayers, in which the superconducting transition temperature Tc is controlled by the angle φ between the magnetic moments of the F layers separated by a nonmagnetic metallic spacer N. Here we present an experimental study of SSE in Nb/Co/Cu/Co/CoO nanowires measured as a function of bias current flowing in the plane of the layers. These measurements reveal an unexpected dependence of Tc(φ) on the bias current: Tc(π)-Tc(0) changes sign with increasing current bias. We attribute the origin of this bias dependence of the SSE to a spin Hall current flowing perpendicular to the plane of the multilayer, which suppresses Tc of the multilayer. The bias dependence of SSE can be important for hybrid F/S devices such as those used in cryogenic memory for superconducting computers as device dimensions are scaled down to the nanometer length scale. arXiv:1908.03612v1 [cond-mat.supr-con]

show abstract

Orientation-dependent Andreev reflection in an altermagnet/altermagnet/superconductor junction

Niu,

Yang

2024

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Altermagnets, an emerging class of magnetic materials distinguished by a significant non-relativistic spin splitting band structure but zero net macroscopic magnetization, have recently received considerable attention. Here, we present a theoretical study focusing on the orientation-dependent conductance induced by Andreev reflection (AR) at an altermagnet/altermagnet/superconductor junction. Conventional and equal-spin AR processes occur when the Néel vector directions of the AMs are non-collinear and controllable by the altermagnet’s orientation θ and Néel vector direction α. The conductance spectra resemble ferromagnet/ferromagnet/superconductor junctions with parallel or antiparallel magnetization configurations, depending on θ and α. Both the anisotropic altermagnetic state and the equal-spin AR signature can be probed by studying conductance spectra. These findings suggest that altermagnet/superconductor junctions are promising platforms for future superconducting spintronics applications.

show abstract

Transport in ferromagnet/superconductor spin valves

Cited by 16 publications

References 54 publications

Spin current and spin transfer torque in ferromagnet/superconductor spin valves

Spin current and spin transfer torque in ferromagnet/superconductor spin valves

Bias current dependence of superconducting transition temperature in superconducting spin-valve nanowires

Orientation-dependent Andreev reflection in an altermagnet/altermagnet/superconductor junction

Contact Info

Product

Resources

About