Quantum Gates via Dynamical Decoupling of Central Qubit on IBMQ and 15NV Center in Diamond

Abstract

We demonstrate a hardware-agnostic protocol for realizing fast, high-fidelity gates through dynamical decoupling (DD) pulse sequences applied to a central qubit coupled to target qubits. The target qubits are controlled by leveraging their intrinsic interaction with the central qubit, eliminating the need for slow, error-prone direct control. We develop and implement the DD-gate protocol within two distinct frameworks: a general model with minimal assumptions, benchmarked on a gate-based digital quantum simulator given by the IBMQ; and an experimentally realistic case with a nitrogen-15 vacancy center ($^{15}$NV) in diamond. Using IBMQ, we are able to elucidate the underlying quantum dynamics of the DD-gates and test them, independently of experimental constraints. For $^{15}$NV, we realize the protocol considering system-specific properties, which could represent a significant reduction in gate duration and improved technological scalability compared with current dynamical-decoupling-based control. We also propose a simple application for high-efficiency polarization of the $^{15}$N nuclear spin that could potentially be less technically demanding than current methods. Altogether, this work provides a robust strategy for quantum control that can be implemented in arbitrary systems fitting the central-target qubit architecture. Beyond these results, our open-source simulations and implementations for both platforms provide a practical framework for simulating time-dependent qubit dynamics on NISQ-era gate-based quantum processors.