Controlled-NOT gate sequences for mixed spin qubit architectures in a noisy environment

TL;DR

This paper develops explicit controlled-NOT gate sequences for mixed spin qubit systems in noisy environments, utilizing genetic algorithms and exchange interactions in quantum dot architectures for scalable quantum computing.

Contribution

It introduces novel CNOT gate sequences tailored for mixed spin qubits in quantum dots, accounting for realistic noise and control limitations.

Findings

Gate infidelity analysis shows robustness against charge noise.

Genetic algorithm optimizes gate sequences considering physical constraints.

Effective Hamiltonians enable precise control in complex geometries.

Abstract

Explicit controlled-NOT gate sequences between two qubits of different types are presented in view of applications for large-scale quantum computation. Here, the building blocks for such composite systems are qubits based on the electrostatically confined electronic spin in semiconductor quantum dots. For each system the effective Hamiltonian models expressed by only exchange interactions between pair of electrons are exploited in two different geometrical configurations. A numerical genetic algorithm that takes into account the realistic physical parameters involved is adopted. Gate operations are addressed by modulating the tunneling barriers and the energy offsets between different couple of quantum dots. Gate infidelities are calculated considering limitations due to unideal control of gate sequence pulses, hyperfine interaction and charge noise.