Microscopic theory of the Coulomb based exchange coupling in magnetic tunnel junctions
arXiv:1607.00403 · doi:10.1088/1361-648X/aa6647
Abstract
We study interlayer exchange coupling (IEC) based on the many-body Coulomb interaction between conduction electrons in magnetic tunnel junction (MTJ). This mechanism complements the known IEC based on virtual electron hopping (or spin currents). We find that these two mechanisms have different behavior on system parameters. The Coulomb based IEC may exceed the hopping based exchange coupling. We show that the Coulomb based exchange coupling, in contrast to the hopping based coupling, depends strongly on the dielectric constant of the insulating layer. The dependence of the IEC on the dielectric properties of the insulating layer in MTJ is similar to magneto-electric (ME) effect where electric and magnetic degrees of freedom are coupled. We calculate the IEC as a function of temperature and electric field for MTJ with ferroelectric (FE) layer and show that IEC has a sharp decrease in the vicinity of the FE phase transition and varies strongly with external electric field.
12 pages, 9 figures
References in corpus (8)
- Anomalous Bias Dependence of Spin Torque in Magnetic Tunnel Junctions
- Spin-transfer torque in magnetic tunnel junctions: Scattering theory
- Bias dependence of magnetic exchange interactions: application to interlayer exchange coupling in spin valves
- Dielectric sensing by charging energy modulation in a nano-granular metal
- Coupling of (ferro)electricity and magnetism through Coulomb blockade in Composite Multiferroics
- Electric field control of magnetic properties and magneto-transport in composite multiferroics
- Probing near-interface ferroelectricity by conductance modulation of a nano-granular metal
- Influence of the Coulomb interaction on the exchange coupling in granular magnets