Coherent population transfer in a chain of tunnel coupled quantum dots

TL;DR

This paper analyzes how to achieve complete and controlled coherent population transfer in a chain of tunnel-coupled quantum dots, drawing analogies with laser-driven atomic systems, with potential applications in quantum computing.

Contribution

It introduces two regimes for population transfer in quantum dot chains, including a STIRAP-like technique, expanding control methods in solid-state quantum systems.

Findings

Periodic population flow achieved through coupling strength arrangement.

Counterintuitive coupling sequence enables coherent trapping and transfer.

Potential applications in quantum computation schemes.

Abstract

We consider the dynamics of a single electron in a chain of tunnel coupled quantum dots, exploring the formal analogies of this system with some of the laser-driven multilevel atomic or molecular systems studied by Bruce W. Shore and collaborators over the last 30 years. In particular, we describe two regimes for achieving complete coherent transfer of population in such a multistate system. In the first regime, by carefully arranging the coupling strengths, the flow of population between the states of the system can be made periodic in time. In the second regime, by employing a "counterintuitive" sequence of couplings, the coherent population trapping eigenstate of the system can be rotated from the initial to the final desired state, which is an equivalent of the STIRAP technique for atoms or molecules. Our results may be useful in future quantum computation schemes.