Wavelet-based Ramsey magnetometry enhancement of a single NV center in diamond

Nitrogen-vacancy (NV) centers in diamond constitute a solid-state nanosensing paradigm. Specifically for high-precision magnetometry, the so-called Ramsey interferometry is the prevalent choice where the sensing signal is extracted from time-resolved spin-state-dependent photoluminescence (PL) data. Its sensitivity is ultimately limited by the photon shot noise (PSN), which cannot be sufficiently removed by averaging or frequency filtering. Here, we propose Ramsey DC magnetometry of a single NV center enhanced by a wavelet-denoising scheme specifically tailored to suppress PSN. It simply operates as a post-processing applied on a collected PL time series. Our implementation is based on template margin thresholding which we computationally benchmark, and demonstrate its signal-to-noise-ratio improvement over the standard quantum limit by up to an order of magnitude for the case of limited-time-budget measurements.Comment: 10 pages, 3 figures, comments are welcom

Nano ölçekli spin hamamları için enaltyapı ve dörtkutup etkileşimleri altında loschmidt yankısı

Cataloged from PDF version of article.Thesis (M.S.): Bilkent University, Department of Physics, İhsan Doğramacı Bilkent University, 2018.Includes bibliographical references (leaves 36-42).Environmental dynamics in solid state matrix is of much importance for quantum information processing and storage purposes. Here, we first give a basic recipe to get Loschmidt echo (LE) which is a measure of decoherence (loss of information from the qubit) in heterogeneously interacting nuclear spin bath (NSB) in the presence of Fermi-contact hyperfine and nuclear spin dipole-dipole interactions. Then, by dropping the latter we discuss the basic dependencies of pure-dephasing regime on size, initial polarization, hyperfine coupling inhomogeneity, spin quantum number in nuclear spin environments, and arrive at a phenomenological expression that governs all these attributes. For NSBs consisting of spin-I ≥ 1, the effect of nuclear electric quadrupole interaction is also considered where its biaxiality term has an in uence on the decoherence process. Furthermore, a general decoherence channel is also employed to see how phase- ip rate affects LE. After insights gained from these models, we consider two generic realistic systems, namely, donor center and quantum dot and explain the power spectral density of LE in these cases.by Ekrem Taha Güldeste.M.S