Engineering spin polarization in a driven multistranded magnetic quantum network

Possible Routes to Obtain Enhanced Magnetoresistance in a Driven Quantum Heterostructure with a Quasi-Periodic Spacer

“… is the fermionic creation (annihilation) operator for the n th site and their components obey anticommutation relation. The first term of Equation ( 2 ) denotes the on-site energy of magnetic chains in the presence of a spin-flip scattering mechanism [ 18 , 60 , 61 ] between the magnetic moments of the n th site and the incoming electron, and consequently, the potential profiles of the electrons belonging to two spin states become separated. is the potential energy at the n th site without any kind of interaction term.…”

“…Experimentally, it was found that the presence of a non-magnetic (NM) spacer having a few atomic layer thick (less than a mean free path of conduction electrons to maintain the GMR effect), sandwiched between ferromagnetic multilayers under applied magnetic field, caused a significant reduction in electrical resistance [23,29,[57][58][59]. The work Grünberg et al [6,29] was associated with a trilayer structure of Fe/Cr/Fe, whereas the discovery of Fert et al [9,26] belonged to several layers (60) of Fe/Cr. The value of GMR decreased by almost 50% in the latter case as it was performed at the temperature 4.2 K, whereas the other one achieved 10% at room temperature, with three Fe layers separated by two Cr layers.…”

“…It is straightforward to understand that, if the magnetization of the free layer is kept parallel to the fixed one, resistance becomes very low due to low scattering rates, and an antiparallel orientation suggests a high scattering rate, yielding a large resistance. Now, this spin-dependent transport [ 32 , 55 , 60 , 61 ] behavior can be tuned externally by modifying the characteristics of NM spacer and ferromagnetic layers. The site energies of the NM spacer is altered by cosine modulation following the AAH form [ 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 ], whereas the hopping parameter in ferromagnetic chains is rearranged by Floquet–Bloch anstaz [ 60 , 74 , 75 , 76 , 77 , 78 , 79 ] within a minimal coupling scheme due to light irradiation on them.…”

“…Now, this spin-dependent transport [ 32 , 55 , 60 , 61 ] behavior can be tuned externally by modifying the characteristics of NM spacer and ferromagnetic layers. The site energies of the NM spacer is altered by cosine modulation following the AAH form [ 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 ], whereas the hopping parameter in ferromagnetic chains is rearranged by Floquet–Bloch anstaz [ 60 , 74 , 75 , 76 , 77 , 78 , 79 ] within a minimal coupling scheme due to light irradiation on them. The Hamiltonian of a layered nanojunction is constructed with the TB approximation [ 31 , 67 ] including only the contribution from the nearest-neighbor hopping (NNH) integral.…”

Possible route to efficient thermoelectric applications in a driven fractal network

“…The SPG is driven by an arbitrarily polarized light, and its effect is incorporated through the standard Floquet-Bloch ansatz in the minimal coupling scheme 13 , 24 – 30 . The mobility edge is detected by superimposing the energy eigenvalues of the non-interacting electrons and the two-terminal transmission probability.…”