Phys Rev Lett
Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA.
Published: June 2015
We demonstrate optically pumped dynamic nuclear polarization of (29)Si nuclear spins that are strongly coupled to paramagnetic color centers in 4H- and 6H-SiC. The 99%±1% degree of polarization that we observe at room temperature corresponds to an effective nuclear temperature of 5 μK. By combining ab initio theory with the experimental identification of the color centers' optically excited states, we quantitatively model how the polarization derives from hyperfine-mediated level anticrossings. These results lay a foundation for SiC-based quantum memories, nuclear gyroscopes, and hyperpolarized probes for magnetic resonance imaging.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.114.247603 | DOI Listing |
Phys Chem Chem Phys
January 2025
Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, USA.
Photosynthetic reaction center proteins (RCs) provide ideal model systems for studying quantum entanglement between multiple spins, a quantum mechanical phenomenon wherein the properties of the entangled particles become inherently correlated. Following light-generated sequential electron transfer, RCs generate spin-correlated radical pairs (SCRPs), also referred to as entangled spin qubit (radical) pairs (SQPs). Understanding and controlling coherence mechanisms in SCRP/SQPs is important for realizing practical uses of electron spin qubits in quantum sensing applications.
View Article and Find Full Text PDFACS Nano
January 2025
IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120, United States.
Lanthanide atoms show long magnetic lifetimes because of their strongly localized 4 electrons, but electrical control of their spins has been difficult because of their closed valence shell configurations. We achieved electron spin resonance of individual lanthanide atoms using a scanning tunneling microscope to probe the atoms bound to a protective insulating film. The atoms on this surface formed a singly charged cation state having an unpaired 6 electron, enabling tunnel current to access their 4 electrons.
View Article and Find Full Text PDFHeliyon
January 2025
Institute of Mathematics, Henan Academy of Sciences, Zhengzhou, 450046, China.
This study examines the behavior of the Casson nanofluid bioconvection flow around a spinning disc under various influences, including gyrotactic microorganisms, multiple slips, and thermal radiation. Notably, it accounts for the reversible nature of the flow and incorporates the esterification process. The aim of this study is to investigate the influence of reversible chemical reactions on the flow behavior of a Casson nanofluid in the presence of bioconvective microorganisms over a spinning disc.
View Article and Find Full Text PDFJ Magn Reson
December 2024
Oral Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Gothenburg, Sweden.
A new 3.2 mm H-F-X magic angle spinning dynamic nuclear polarization NMR (MAS DNP-NMR) probe was developed with a unique coil design with separate radiofrequency channels for H excitation and C or F detection to enable acquisition of H-F cross-polarization (CP) MAS experiments, direct-detected F spectra with proton decoupling, and acquisition on C with simultaneous double decoupling on the H and 19F channels as well as H-F-C double-CP experiments under low temperature MAS DNP conditions. We use these sequences to study AZD2811, which is an active pharmaceutical ingredient (API), in its pure dry state as well as in its corresponding drug delivery formulation consisting of drug-loaded polymeric nanoparticles (PNPs).
View Article and Find Full Text PDFJ Chem Phys
January 2025
Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 76100, Israel.
The sensitivity of solid state nuclear magnetic resonance spectroscopy can be enhanced via dynamic nuclear polarization (DNP) using unpaired electrons as polarizing agents. In metal ions based (MI)-DNP, paramagnetic metal ions are introduced as dopants into inorganic materials serving as endogenous polarizing agents. Having polarizing agents as part of the structure enables signal enhancements within the bulk of the material.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!
© LitMetric 2025. All rights reserved.