First-principles study on tunnel magnetoresistance effect with Cr-doped RuO_2 electrode

We investigate the functionality of the Cr-doped RuO_2 as an electrode of the magnetic tunnel junction (MTJ), motivated by the recent experiment showing that Cr-doping into the rutile-type RuO_2 will be an effective tool to control its antiferromagnetic order and the resultant magnetotransport phenomena easily. We perform first-principles calculation of the tunnel magnetoresistance (TMR) effect in the MTJ based on the Cr-doped RuO_2 electrodes. We find that a finite TMR effect appears in the MTJ originating from the momentum-dependent spin splitting in the electrodes, which suggests that RuO_2 with Cr-doping will work as the electrode of the MTJ. We also show that this TMR effect can be qualitatively captured using the local density of states inside the tunnel barrier.