Graphene Enabled Low-Control Quantum Gates between Static and Mobile Spins

TL;DR

This paper proposes a novel quantum gate mechanism in graphene leveraging Klein tunneling, enabling deterministic interactions between static and mobile spins regardless of electron momentum or wave shape.

Contribution

It introduces a low control quantum gate design using graphene's Klein tunneling, facilitating interactions between static and mobile qubits with minimal back-scattering.

Findings

Klein tunneling enables quasi-deterministic quantum gates.

The model allows entanglement generation between static qubits.

Graphene's properties are exploited for robust quantum gate implementation.

Abstract

We show that the feature of Klein tunneling makes graphene a unique interface for implementing low control quantum gates between static and mobile qubits. A ballistic electron spin is considered as the mobile qubit, while the static qubit is the electronic spin of a quantum dot fixed in a graphene nanoribbon. Scattering is the low control mechanism of the gate, which, in other systems, is really difficult to exploit because of both back-scattering and the momentum dependence of scattering. We find that Klein tunneling enables the implementation of quasi-deterministic quantum gates regardless of the momenta or the shape of the wave function of the incident electron. The Dirac equation is used to describe the system in the one particle approximation with the interaction between the static and the mobile spins modelled by a Heisenberg Hamiltonian. Furthermore, we discuss an application of this model to generate entanglement between two well separated static qubits.