A Hahn-Ramsey Scheme for Dynamical Decoupling and DC Magnetometry with Single Solid-State Qubits

TL;DR

This paper introduces a Hahn-Ramsey control scheme using RF pulse detuning to enhance spin coherence and DC magnetometry sensitivity in solid-state qubits, demonstrated on NV centers in diamond.

Contribution

It presents a novel control sequence that improves spin phase oscillation visibility and DC magnetic field sensitivity by modulating the filter function through RF detuning.

Findings

Enhanced Ramsey fringe visibility comparable to Hahn-echo T2 time.

Improved DC magnetic field sensitivity in experimental setups.

Experimental validation on single NV centers in diamond.

Abstract

Spin systems in solid state materials are promising qubit candidates for quantum information or quantum sensing. A major prerequisite here is the coherence of spin phase oscillations. In this work, we show a control sequence which, by applying RF pulses of variable detuning, allows to increase the spin phase oscillation visibility and to perform DC magnetometry as well. We experimentally demonstrate the scheme on single NV centers in diamond and analytically describe how the NV electron spin phase oscillations behave in the presence of classical noise models. We hereby introduce detuning as the enabling factor that modulates the filter function of the sequence, in order to achieve a visibility of the Ramsey fringes comparable to or longer than the Hahn-echo $T_2$ time and an improved sensitivity to DC magnetic fields in various experimental settings.