Inelastic tunnel transport of electrons through an anisotropic magnetic structure in an external magnetic field

• Published in: Journal of experimental and theoretical physics Vol. 119; no. 1; pp. 124 - 137
• Main Authors: Val’kov, V. V., Aksenov, S. V., Ulanov, E. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.07.2014; Springer
• Subjects: Anisotropy; Classical and Quantum Gravitation; Electron transport; Electronic Properties of Solid; Electrons; Elementary Particles; Magnetic fields; Particle and Nuclear Physics; Physics; Physics and Astronomy; Quantum Field Theory; Relativity Theory; Solid State Physics; Spectral Function; Magnetic Impurity; Nega Tive Differential Conductivity; Versus Curve; Occupation Number
• ISSN: 1063-7761; 1090-6509
• DOI: 10.1134/S1063776114060065

Quantum transport of electrons through a magnetic impurity located in an external magnetic field and affected by a substrate is considered using the Keldysh diagram technique for the Fermi and Hubbard operators. It is shown that in a strongly nonequilibrium state induced by multiple reflections of electrons from the impurity, the current-voltage ( I–V ) characteristic of the system contains segments with a negative conductivity. This effect can be controlled by varying the anisotropy parameter of the impurity center as well as the parameters of coupling between the magnetic impurity and metal contacts. The application of the magnetic field is accompanied by an increase in the number of Coulomb steps in the I–V curve of the impurity. The effect of appreciable magnetoresistance appears in this case. We demonstrate the possibility of switching between magnetic impurity states with different total spin projection values in the regime of asymmetric coupling of this impurity with the contacts.