A key challenge of magnetometry lies in the simultaneous optimization of magnetic field sensitivity and maximum field range. In interferometry-based magnetometry, a quantum two-level system acquires a dynamic phase in response to an applied magnetic field. However, due to the 2π periodicity of the phase, increasing the coherent interrogation time to improve sensitivity reduces field range. Here we introduce a route towards both large magnetic field range and high sensitivity via measurements of the geometric phase acquired by a quantum two-level system. We experimentally demonstrate geometric-phase magnetometry using the electronic spin associated with the nitrogen vacancy (NV) color center in diamond. Our approach enables unwrapping of the 2π phase ambiguity, enhancing field range by 400 times. We also find additional sensitivity improvement in the nonadiabatic regime, and study how geometric-phase decoherence depends on adiabaticity. Our results show that the geometric phase can be a versatile tool for quantum sensing applications.A key challenge of magnetometry lies in the simultaneous optimization of magnetic field sensitivity and maximum field range. In interferometry-based magnetometry, a quantum two-level system acquires a dynamic phase in response to an applied magnetic field. However, due to the 2π periodicity of the phase, increasing the coherent interrogation time to improve sensitivity reduces field range. Here we introduce a route towards both large magnetic field range and high sensitivity via measurements of the geometric phase acquired by a quantum two-level system. We experimentally demonstrate geometric-phase magnetometry using the electronic spin associated with the nitrogen vacancy (NV) color center in diamond. Our approach enables unwrapping of the 2π phase ambiguity, enhancing field range by 400 times. We also find additional sensitivity improvement in the nonadiabatic regime, and study how geometric-phase decoherence depends on adiabaticity. Our results show that the geometric phase can be a versatile tool for quantum sensing applications.

arXiv:1803.07176Nature CommunicationsNov 21, 201834 citations

Precision Magnetometry Using Ensembles of NV Spins in Diamond

David Le Sage, Linh Pham, David R. Glenn +9 more

APSMar 1, 20100 citations

On the Formation of Dense Arrays of Nitrogen–Vacancy Centers in Synthetic Single-Crystal Diamonds for Quantum Sensors

Сергей Александрович Тарелкин, Stepan V. Bolshedvorskii, С.Г. Буга +10 more

The dynamics of the formation of ensembles of nitrogen–vacancy color centers (NV centers) in single-crystal diamond plates after irradiation by high-energy (2 MeV) electrons and subsequent annealing is investigated. The concentration of the nitrogen impurity is determined from the infrared (IR) absorption spectrum to be 90 and 4 ppm for the diamond growth sectors {111} and {001}, respectively. The transverse relaxation times $T_{2}^{*}$ for the electron spin of NV centers are studied; they are found to amount to 200 and 900 ns for the {111} and {001} sectors, respectively, and are limited by the concentration of paramagnetic impurity defects in diamond. The sensitivity of quantum sensors based on the obtained ensembles of NV centers is estimated; the estimation shows feasibility of using denser ensembles in low-field magnetometry.The dynamics of the formation of ensembles of nitrogen–vacancy color centers (NV centers) in single-crystal diamond plates after irradiation by high-energy (2 MeV) electrons and subsequent annealing is investigated. The concentration of the nitrogen impurity is determined from the infrared (IR) absorption spectrum to be 90 and 4 ppm for the diamond growth sectors {111} and {001}, respectively. The transverse relaxation times $$T_{2}^{*}$$ for the electron spin of NV centers are studied; they are found to amount to 200 and 900 ns for the {111} and {001} sectors, respectively, and are limited by the concentration of paramagnetic impurity defects in diamond. The sensitivity of quantum sensors based on the obtained ensembles of NV centers is estimated; the estimation shows feasibility of using denser ensembles in low-field magnetometry.

Nanobiotechnology ReportsAug 1, 20221 citation

Time-resolved magnetic sensing with electronic spins in diamond

A. Cooper, Easwar Magesan, H. Yum +1 more

arXiv:1305.6082Nature CommunicationsJan 24, 201473 citations

Robust diamond-defect magnetometry

Johanna L. Miller

Physics TodayJun 20, 20180 citations

T_{2}^{*}

for the electron spin of NV centers are studied; they are found to amount to 200 and 900 ns for the {111} and {001} sectors, respectively, and are limited by the concentration of paramagnetic impurity defects in diamond. The sensitivity of quantum sensors based on the obtained ensembles of NV centers is estimated; the estimation shows feasibility of using denser ensembles in low-field magnetometry.