Fast manipulation of a single electron along a quantum dot chain

Abstract

We present a protocol based on shortcuts to adiabaticity for the manipulation of an electron in a linear quantum dot array of arbitrary size on an InSb heterostructure. We propose a model where the couplings between neighboring dots have a particular form, related to a spin operator that depends on the size of the chain. The system is driven by an electric field with a modified Landau-Zener time-dependence. We find that the transmission of the electron from the first site to the last one can be achieved with any desired fidelity (99.9% or even more) by choosing the appropriate evolution time of the system according to the length of the chain. Then, we consider Rashba spin-orbit (SO) interaction effects and possible chain defects and find that transmission probabilities are larger than 90% for moderate intensity of SO interactions. However, we can increase even more the fidelity by increasing the static magnetic field, since it would diminish the effect of the SO mechanism in the dynamics.