In this work, we study the development of a coplanar waveguide (CPW) resonator and its use in an electron spin resonance (ESR) spectrometer. The CPW resonator is designed to operate in S-band (2-4 GHz), with a short circuit configuration leading to miniaturization. It is so constructed such that it has a characteristic impedance of 50 ohms. The resonator supports quasi-TEM mode of propagation owing to its uniplanar nature, demanding detailed electromagnetic simulation. The design parameters and the electromagnetic field distribution are obtained from the simulation. The resonator is fabricated using optical lithography with a rapid prototyping technique. The characteristic response of the resonator is measured by coupling it to a Vector Network Analyzer (VNA). The ESR absorption spectrum of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) is captured by using this resonator in reflection geometry. The microwave magnetic field distribution at the sample position is investigated. The ascertained value of Lande g-factor is consistent with that reported in the literature. Spin sensitivity of the order of 1015 spins/gauss is achieved upon using this resonator at room temperature. The quality factor of this resonator is found to be low and this makes it suitable for use in a Pulsed ESR spectrometer.
In this study, novel use of the electromagnetic field profile of a localized spoof surface plasmonic mode to detect electron spin resonance (ESR) is being reported. The mode is supported on a resonator with a complementary metallic spiral structure, etched on the ground plane of a microstrip line having a characteristic impedance of 50 Ω. The change in characteristics of the mode of interest with lowering of temperature has been observed and analyzed. ESR spectra of three paramagnetic samples—2,2-diphenyl-1-picrylhydrazyl (DPPH), galvinoxyl, and 2,2,6,6-tetramethylpiperidine-1-oxyl are recorded using this resonator at room temperature. ESR spectra of DPPH are also captured down to 10 K. Potential application of the mode in the detection of microwave induced Rashba field-driven ESR has been discussed.
We demonstrate a room-temperature optically induced magnetic field for nitrogen-vacancy centers in diamond. The effective magnetic field i s d etermined b y the photonic spin density of a red-detuned optical excitation. This opens a new frontier for studying exotic phases of photons as well as future on-chip applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.