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

• Published in: Micromachines (Basel) Vol. 12; no. 9; p. 1021
• Main Authors: Koley, Arpita, Maiti, Santanu K., Pérez, Laura M., Silva, Judith Helena Ojeda, Laroze, David
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 27.08.2021; MDPI
• Subjects: Ferromagnetism; Floquet–Bloch ansatz; Green’s function formalism; Heterostructures; Light; Light irradiation; Magnetic fields; Magnetic properties; Magnetism; Magnetoresistance; Magnetoresistivity; quasi-periodic spacer; Temperature effects; tight binding framework; Transport properties
• ISSN: 2072-666X; 2072-666X
• DOI: 10.3390/mi12091021

In this work, we perform a numerical study of magnetoresistance in a one-dimensional quantum heterostructure, where the change in electrical resistance is measured between parallel and antiparallel configurations of magnetic layers. This layered structure also incorporates a non-magnetic spacer, subjected to quasi-periodic potentials, which is centrally clamped between two ferromagnetic layers. The efficiency of the magnetoresistance is further tuned by injecting unpolarized light on top of the two sided magnetic layers. Modulating the characteristic properties of different layers, the value of magnetoresistance can be enhanced significantly. The site energies of the spacer is modified through the well-known Aubry–André and Harper (AAH) potential, and the hopping parameter of magnetic layers is renormalized due to light irradiation. We describe the Hamiltonian of the layered structure within a tight-binding (TB) framework and investigate the transport properties through this nanojunction following Green’s function formalism. The Floquet–Bloch (FB) anstaz within the minimal coupling scheme is introduced to incorporate the effect of light irradiation in TB Hamiltonian. Several interesting features of magnetotransport properties are represented considering the interplay between cosine modulated site energies of the central region and the hopping integral of the magnetic regions that are subjected to light irradiation. Finally, the effect of temperature on magnetoresistance is also investigated to make the model more realistic and suitable for device designing. Our analysis is purely a numerical one, and it leads to some fundamental prescriptions of obtaining enhanced magnetoresistance in multilayered systems.