Theory of giant magnetoresistance effects in magnetic layered structures with antiferromagnetic coupling

Camley, R. E.; Barnaś, J.

doi:10.1103/physrevlett.63.664

Cited by 865 publications

(306 citation statements)

References 16 publications

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“…When spin-flip scattering is caused by spin-orbit interaction in the normal metal, the spin-diffusion length l s f can be estimated to be equal to l f /(␣Z) 2 , where ␣ is the relativistic fine structure constant, Z is the atomic number, and l f is the mean free path ͑see, e.g., Ref. 20͒.…”

Section: B Spin-flip Scattering Spin Relaxationmentioning

confidence: 99%

“…The discovery of the giant magnetoresistance ͑GMR͒ effect in metallic magnetic multilayers 1 has motivated a large number of studies on the transport properties of such systems. 2 The GMR is caused by spin-dependent scattering in the system. Most studies concentrated on collinear configurations ͑parallel and antiparallel configurations͒.…”

Section: Introductionmentioning

confidence: 99%

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Conductance modulation by spin precession in noncollinear ferromagnet normal-metal ferromagnet systems

et al. 2000

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We study diffusive transport through ferromagnet normal-metal ferromagnet systems, with arbitrary but fixed magnetization directions of the ferromagnetic reservoirs and orientations of a magnetic field applied to the normal metal. For noncollinear configurations, the complex mixing conductance G ↑↓ describes the transport of spins noncollinear to the magnetizations of the ferromagnetic reservoirs. When Im G ↑↓ 0, the total conductance of the system in the presence of a magnetic field can be asymmetric with respect to time reversal. The total conductance changes nonmonotonically with the magnetic field strength for different magnetic configurations. This modulation of the conductance is due to the precession of the spin accumulation in the normal metal. The difference between the conductance of the parallel and antiparallel configurations can be either positive or negative as a function of the applied magnetic field. This effect should be best observable on Al single crystals attached to ferromagnetic electrodes by means of tunnel junctions or metallic contacts.

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Section: B Spin-flip Scattering Spin Relaxationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Conductance modulation by spin precession in noncollinear ferromagnet normal-metal ferromagnet systems

et al. 2000

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“…In other experimental studies the GMR is studied as a function of the thickness of magnetic and nonmagnetic layers, 8,9 leaving the Co/Cu interfaces unchanged. However, experimental verification of the scattering asymmetry for spin-up and spin-down electrons is usually indirect via fits with models such as the resistor network model, 10 models based on the semiclassical Boltzmann transport equation 11 and the quantum model of Zhang, Levy, and Fert. 12 Due to the large number of input parameters the conclusions obtained are often questionable.…”

Section: Introductionmentioning

confidence: 99%

Analysis of scattering lengths in Co/Cu/Co and Co/Cu/Co/Cu spin-valves using a Ru barrier

et al. 1996

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We use uncoupled Co/Cu/Co and Co/Cu/Co/Cu spin-valve structures with a Ru barrier shifted through the top Co and Cu layer, respectively, to measure the longest of the electron mean free paths in Co and Cu as originally suggested by Parkin. From semiclassical transport calculations and careful analysis of the magnetoresistance data we conclude that the exponential behavior of ⌬G is uniquely related to the longest of the Co and Cu mean free paths under the condition of effective spin-dependent filtering at the interfaces or in the bulk of the Co. In this regime we have compared long in Co and Cu with bulk conductivities ͑ϰ short ϩ long ͒, yielding no strong evidence for bulk spin-dependent scattering in Co. ͓S0163-1829͑96͒02037-1͔

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“…As known [14,23], everything else being equal, ρ J 2 ≫ ρ J 1 since the AFM scattering (J 2 < 0) admits a spin-flip processes thereby increasing the scattering amplitude which allows to consider the component ρ J 1 corresponding to the FM exchange prevailing. Since the resistance is proportional to the square of the scattering amplitude which, in turn, according to Eq.…”

mentioning

confidence: 99%

“…In this structure, only superconductor in the ground normal state may be responsible for negative magnetoresistance at low fields: in accordance with the characteristics of other parts of a contact, copper probes and oxide barriers [12], their magnetoresistance can reveal only slightly increasing behavior in weak magnetic fields. It is known that an increase in conductivity in a magnetic field (except, perhaps, for field values corresponding to large Zeeman energies, capable of, for example, inducing metamagnetism), leading to negative magnetoresistance, indicates either the presence of spin-dependent effects in transport of itinerant conduction electrons [14] or the degradation of weak-localization interference addition to the resistance [15]. Assessing the weak-localization interference correction to the conductivity, we find that the negative contribution to magnetoresistance of the contacts under elastic scattering of electrons (at helium temperatures) due to the destruction of interference self-intersecting trajectories of electrons by a magnetic field in the studied range of fields can be of the following order of magnitude:…”

mentioning

confidence: 99%

Spin-dependent conductivity of iron-based superconductors in a magnetic field

Dzyuba¹,

Chiang²,

Чареев³

et al. 2015

Physica B: Condensed Matter

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We report the results of a study of magnetic field features of electron transport in heterojunctions with NS boundary inside iron-based superconductors, represented by a binary phase of α -FeSe and oxyarsenide pnictide LaO(F)FeAs. We used the ability of self magnetic field of the transport current to partially destroy superconductivity, no matter how low the field may be, in the NS interface area, where, due to the proximity effect, the superconducting order parameter, ∆, disperses from 1 to 0 within the scale of the Ginzburg-Landau coherence length.The following features of transport were found: (i) at T < T c , magnetoresistance in systems with different superconductors has different sign; (ii) sign and magnitude of the magnetoresistance depend on the magnitude of current and temperature, and (iii) in all operating modes where the contribution from Andreev reflection is suppressed ((T + eV ) ∆), the hysteresis of the magnetoresistance is present.Based on the results of the experiment and analysis it has been concluded that there is a longrange magnetic order in the ground normal state of the iron-based superconductors studied, in the presence of itinerant magnetism of conduction electrons which determines the possibility of anisotropic spin-dependent exchange interaction with the local magnetic moments of the ions.Search and study of low-symmetry systems with crystal symmetry of "layered" type, characterized by anisotropic electrical and magnetic properties leading to superconductivity, is one of the most urgent problems of condensed matter physics. Currently, superconductivity is found in the vast family of such compounds containing a wide range of rare earths, pnictogens, chalcogens, and transition elements Mn, Fe, Co, Ni, Cu, Ru. In particular, observation of superconductivity in iron-based structures suggests that it is the anisotropy of the properties that seems to be an essential condition under which in the same material may coexist magnetic interactions and interactions that determine the superconducting pairing of excitations in the electronic subsystem.While the ideas of the crystal structures and nature of coupling in such superconductors are sufficiently developed and experimentally proved, their magnetic and electronic structures, and especially the nature of their interaction in the ground state of iron-based superconductors, are still the subject of intense debate (see, eg, [1, 2]). Therefore, it becomes important to study transport phenomena in the systems containing such superconductors, as the nature of those phenomena may directly depend on itinerant magnetism of conduction electrons, capable of interacting with the sublattice of localized magnetic moments of the magnetic atoms.Here we report the results of studying hysteresis features of electron transport in a magnetic field in the normal ground state of iron-based superconductors, namely, monocrystalline binary phase of α -FeSe and oxyarsenide pnictide LaO(F)FeAs in granular form. Both crystal structures share common structural un...

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Theory of giant magnetoresistance effects in magnetic layered structures with antiferromagnetic coupling

Cited by 865 publications

References 16 publications

Conductance modulation by spin precession in noncollinear ferromagnet normal-metal ferromagnet systems

Conductance modulation by spin precession in noncollinear ferromagnet normal-metal ferromagnet systems

Analysis of scattering lengths in Co/Cu/Co and Co/Cu/Co/Cu spin-valves using a Ru barrier

Spin-dependent conductivity of iron-based superconductors in a magnetic field

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