Authors: M. Stilling, K. Stokbro and K. Flensberg
Affilation: Atomistix, Denmark
Pages: 209 - 211
Keywords: spintronics, magnetotunnel junction, TMR, magnetic random access memory, MRAM, hard disk drive read head, electron transport
Magnetotunnel junctions (MTJs), exhibiting high tunneling magnetoresistance (TMR), are currently being employed in new generations of hard disk drive (HDD) read heads and novel magnetic random access memory (MRAM) technology. We have modeled such spintronic components using the software package Atomistix ToolKit (ATK), which is based on density functional theory (DFT) and non-equilibrium Green’s functions (NEGFs). We have focused on calculating zero-bias conductance and TMR for crystalline Fe-MgO-Fe MTJs, and have studied the effects of different oxide layers in the Fe/MgO interface, and the effects of structural “disorder” in the device. We find that such “defects” in the atomic structure have strong effects on the conductance. We use the result of the calculations to rationalize recent experimental findings.