Manipulating spin transfer torque with light

作者：Vendelbjerg Karsten Leding; Rontani Massimo^*

来源：Superlattices and Microstructures, 2017, 108: 64-72.

DOI：10.1016/j.spmi.2016.12.047

• Spin transfer torque
• Optical Stark effect
• Fano resonance

We study the spin transfer torque (STT) induced onto a nanomagnet as a spin-polarized current flows through a junction made of the magnet sandwiched between two semiconductors. This junction is one-dimensional and highly idealized, the thin magnetic layer being mimicked by a spin-dependent contact force. We show that the STT may be externally controlled by shining the junction at sub-bandgap frequency with an intense laser beam. The excitonic coherence driven by the laser dresses the virtual electron-hole pairs coupling conduction and valence bands and inducing evanescent waves at the junction interface. The Fano-like quantum interference between these localized states and the continuum spectrum, being different in the two spin channels, significantly affects the STT.

• 出版日期2017-8