Indirect exciton qubit manipulation via the optical Stark effect in quantum dot molecules

TL;DR

This paper introduces a novel all-optical method for manipulating indirect exciton qubits in quantum dot molecules using the optical Stark effect, enabling quantum gate operations through dynamic energy level control.

Contribution

It presents a new control scheme combining voltage bias and optical pulses to coherently manipulate indirect excitons for quantum computing applications.

Findings

Demonstrates dynamic generation and modification of anticrossing gaps.

Shows coherent population trapping of indirect excitons.

Enables implementation of quantum gates like Pauli-X and Hadamard.

Abstract

We propose a coherent control scheme based on the optical Stark effect in optically generated excitons in quantum dot molecules (QDMs). We show that, by the combined action of voltage bias detuning sweeps and Rosen-Zener pulsed interactions, it is possible to dynamically generate and modify an anticrossing gap that emerges between the dressed energy levels of long-lived, spatially indirect excitons. We perform numerical and analytic non-perturbative calculations based on the Bloch-Feshbach formalism, which demonstrate that this effect induces a mechanism of coherent population trapping of indirect excitons in QDMs. Our results show that it is possible to perform an all-optical implementation of indirect-excitonic qubit operations, such as the Pauli-X and Hadamard quantum gates, across two defined axis of the Bloch Sphere.