Experimental protection of 2-qubit quantum gates against environmental noise by dynamical decoupling

TL;DR

This paper demonstrates that dynamical decoupling can effectively protect 2-qubit quantum gates from environmental noise in a nitrogen-vacancy center, significantly extending coherence times without disrupting quantum operations.

Contribution

It provides experimental validation of a protection scheme for hybrid qubits, showing compatibility of dynamical decoupling with quantum gate processing.

Findings

Dephasing time extended close to electron spin relaxation limit

Protection scheme compatible with quantum gate operations

Effective noise mitigation in hybrid qubit systems

Abstract

Hybrid systems consisting of different types of qubits are promising for building quantum computers if they combine useful properties of their constituent qubits. However, they also pose additional challenges if one type of qubits is more susceptible to environmental noise than the others. Dynamical decoupling can help to protect such systems by reducing the decoherence due to the environmental noise, but the protection must be designed such that it does not interfere with the control fields driving the logical operations. Here, we test such a protection scheme on a quantum register consisting of the electronic and nuclear spins of a nitrogen-vacancy center in diamond. The results show that processing is compatible with protection: The dephasing time was extended almost to the limit given by the longitudinal relaxation time of the electron spin.