کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1543604 | 1512867 | 2016 | 7 صفحه PDF | دانلود رایگان |
• The study identifies topological insulator edge coupled to nanomagnet as adiabatic quantum motor.
• Landauer–Büttiker theory for Landau–Lifshitz–Gilbert equation of nanomagnet dynamics.
• The study shows that this system realizes a Thouless motor and discusses its efficiency.
The precessing magnetization of a magnetic islands coupled to a quantum spin Hall edge pumps charge along the edge. Conversely, a bias voltage applied to the edge makes the magnetization precess. We point out that this device realizes an adiabatic quantum motor and discuss the efficiency of its operation based on a scattering matrix approach akin to Landauer–Büttiker theory. Scattering theory provides a microscopic derivation of the Landau–Lifshitz–Gilbert equation for the magnetization dynamics of the device, including spin-transfer torque, Gilbert damping, and Langevin torque. We find that the device can be viewed as a Thouless motor, attaining unit efficiency when the chemical potential of the edge states falls into the magnetization-induced gap. For more general parameters, we characterize the device by means of a figure of merit analogous to the ZT value in thermoelectrics.
Journal: Physica E: Low-dimensional Systems and Nanostructures - Volume 82, August 2016, Pages 247–253