Robust Dynamical Decoupling for Arbitrary Quantum States of a Single NV Center in Diamond

TL;DR

This paper demonstrates that dynamical decoupling can significantly extend the coherence time of a single NV center's electron spin in diamond, achieving near T1 limits and robust performance across various initial states.

Contribution

It introduces a robust dynamical decoupling method optimized for arbitrary quantum states of a single NV center in diamond.

Findings

Decoherence time extended up to 2.2 ms, close to T1 of 4 ms.

Dynamical decoupling sequences show robustness to initial state variations.

Performance is resilient to experimental imperfections.

Abstract

Dynamical decoupling is a powerful technique for extending the coherence time (T$_2$) of qubits. We apply this technique to the electron spin qubit of a single nitrogen-vacancy center in type IIa diamond. In a crystal with natural abundance of $^{13}$C nuclear spins, we extend the decoherence time up to 2.2 ms. This is close to the T$_1$ value of this NV center (4 ms). Since dynamical decoupling must perform well for arbitrary initial conditions, we measured the dependence on the initial state and compared the performance of different sequences with respect to initial state dependence and robustness to experimental imperfections.