Fast long-range state transfer in quantum dot arrays via shortcuts to adiabaticity

TL;DR

This paper introduces a protocol using shortcuts to adiabaticity to enable fast, robust quantum state transfer in quantum dot arrays, minimizing decoherence and improving quantum information processing efficiency.

Contribution

It develops a method combining counterdiabatic driving and inverse engineering to accelerate charge transfer in multi-quantum dot systems without populating intermediate dots.

Findings

Achieved fast adiabatic-like charge transfer between outer dots.

Transfer fidelity depends on operation time and dephasing.

Protocol reduces decoherence effects during transfer.

Abstract

Rapid and efficient preparation, manipulation and transfer of quantum states through an array of quantum dots (QDs) is a demanding requisite task for quantum information processing and quantum computation in solid-state physics. Conventional adiabatic protocols, as coherent transfer by adiabatic passage (CTAP) and its variations, provide slow transfer prone to decoherence, which could lower the fidelity to some extent. To achieve the robustness against decoherence, we propose a protocol of speeding up the adiabatic charge transfer in multi-QD systems, sharing the concept of "Shortcuts to Adiabaticity" (STA). We first apply the STA techniques, including the counterdiabatic driving and inverse engineering, to speed up the direct (long range) transfer between edge dots in triple QDs. Then, we extend our analysis to a multi-dot system. We show how by implementing the modified pulses, fast adiabatic-like charge transport between the outer dots can be eventually achieved without populating intermediate dots. We discuss as well the dependence of the transfer fidelity on the operation time in the presence of dephasing. The proposed protocols for accelerating adiabatic charge transfer directly between the outer dots in a QD array offers a robust mechanism for quantum information processing, by minimizing decoherence and relaxation processes.