Saturday, May 21, 2016

Abstract-Terahertz Antiferromagnetic Spin Hall Nano-Oscillator


Ran Cheng, Di Xiao, and Arne Brataas

We consider the current-induced dynamics of insulating antiferromagnets in a spin Hall geometry. Sufficiently large in-plane currents perpendicular to the Néel order trigger spontaneous oscillations at frequencies between the acoustic and the optical eigenmodes. The direction of the driving current determines the chirality of the excitation. When the current exceeds a threshold, the combined effect of spin pumping and current-induced torques introduces a dynamic feedback that sustains steady-state oscillations with amplitudes controllable via the applied current. The ac voltage output is calculated numerically as a function of the dc current input for different feedback strengths. Our findings open a route towards terahertz antiferromagnetic spin-torque oscillators.
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 30 September 2015
DOI:http://dx.doi.org/10.1103/PhysRevLett.116.207603
© 2016 American Physical Society

No comments: