A proposed spin qubit CNOT gate robust against noisy coupling

TL;DR

This paper proposes a robust two-qubit CNOT gate for quantum dot spin qubits that is immune to charge noise by using an auxiliary dot and adiabatic passage techniques, enhancing gate stability.

Contribution

It introduces a novel implementation of a noise-resistant two-qubit gate using adiabatic passage and an auxiliary dot in quantum dot spin systems.

Findings

The proposed gate is theoretically immune to charge noise.

Utilizes an auxiliary dot and adiabatic passage for robust operation.

Potential for improved fidelity in quantum dot quantum computing.

Abstract

We propose an implementation of the two-qubit gate in a quantum dot spin qubit system which is immune to charge noise problems. Our proposed implementation, if it could be realized in a physical system, would have the advantage of being robust against uncertainties and fluctuations in the tunnel coupling and barrier gate voltage pulse area. The key idea is to introduce an auxiliary dot and use an analog to the stimulated Raman adiabatic passage pulse sequence in three-level atomic systems, often referred to in the context of electron transport in quantum dot systems as Coherent Tunneling by Adiabatic Passage. Spin-dependent tunneling opens the possibility of performing two-qubit gate operations by this method.