Photo-induced spin filtering in a double quantum dot

TL;DR

This paper demonstrates how ultrafast electromagnetic pulses can coherently control and spatially separate electron spins in a double quantum dot, enabling spin filtering on femtosecond timescales.

Contribution

It introduces an analytical model showing how specific pulse sequences can achieve and maintain spin-dependent localization in double quantum dots.

Findings

Spin-up electrons can be localized in one dot while spin-down electrons remain in the other.

Spin separation can be maintained for a controllable period.

Ultrafast pulses enable femtosecond-scale spin control.

Abstract

We investigate the spin-resolved electron dynamics in a double quantum dot driven by ultrafast asymmetric electromagnetic pulses. Using a analytical model we show that applying an appropriate pulse sequence allows to control coherently the spin degree of freedom on the femtosecond time scale. It can be achieved that the spin-up state is localized in a selected quantum dot while the spin-down state remains in the other dot. We show that this photo-induced spin-dependent separation can be maintained for a desired period of time.