Controlled Operations in a Strongly Correlated Two-Electron Quantum Ring

TL;DR

This paper investigates the electronic properties of a strongly correlated two-electron quantum ring and introduces a novel qubit scheme utilizing total electron spin and angular momentum, demonstrating high-fidelity quantum gate operations.

Contribution

It presents an exact diagonalization analysis of a two-electron quantum ring and proposes a new qubit encoding scheme with demonstrated near-perfect CNOT gate fidelity.

Findings

Exact diagonalization of the quantum ring spectrum.

Proposed a new qubit scheme combining spin and angular momentum.

Achieved near 100% fidelity in CNOT gate implementation.

Abstract

We have analyzed the electronic spectrum and wave function characteristics of a strongly correlated two-electron quantum ring with model parameters close to those observed in experiments. The analysis is based on an exact diagonalization of the Hamiltonian in a large B-spline basis. We propose a new qubit pair for storing quantum information, where one component is stored in the total electron spin and one multivalued "quMbit" is represented by the total angular momentum. In this scheme the controlled NOT (CNOT) quantum gate is demonstrated with near 100% fidelity for a realistic far infrared electromagnetic pulse.