Article
Chemistry, Analytical
Jonathan R. Birchall, Robert K. Irwin, Md Raduanul H. Chowdhury, Panayiotis Nikolaou, Boyd M. Goodson, Michael J. Barlow, Anton Shcherbakov, Eduard Y. Chekmenev
Summary: This study utilizes NMR and NIR technologies to analyze the Xe-129 hyperpolarization process in detail, aiming to improve production efficiency and stability. Mapping the dynamics of Xe-129 polarization and relaxation at different SEOP temperatures enables systematic optimization of the batch-mode SEOP process.
ANALYTICAL CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
James E. Ball, Jim M. Wild, Graham Norquay
Summary: In this study, we measured the variation of rubidium vapor density in Xe-129-Rb spin-exchange optical pumping using near-infrared and violet atomic absorption spectroscopy. We found that the relationship between spectral absorption and rubidium density does not follow the Beer-Lambert law. The measured rubidium density was used to estimate the spin exchange cross section of Xe-129-Rb, which was consistent with literature values. Additionally, we observed heterogeneity in rubidium density in different reactors with varying distributions and amounts of rubidium metal.
Article
Physics, Applied
Michele Kelley, Rosa Tamara Branca
Summary: The study reveals that the misapplication of spin-exchange optical pumping theory and spin-exchange constants in the past 20 years has contributed to the discrepancy between theoretical and experimental 129Xe polarization values. The correct application of the theory can help accurately predict 129Xe polarization values under various experimental conditions, leading to higher spin-exchange rates than previously assumed in theoretical models.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Zitong Xu, Kai Wei, Xiaofei Huang, Dinghui Gong, Weiyi Wang, Chang Liu, Xing Heng, Fan Wang, Yueyang Zhai, Wei Quan
Summary: In this study, a model of the effective magnetic field gradient caused by uneven spin polarization is established and analyzed. A balanced light-assisted hybrid spin exchange optical pumping (HSEOP) method is proposed to address this issue. Experimental results confirm the effectiveness of this method in suppressing the nuclear transverse relaxation rate and increasing the scale factor, overcoming the limitation of laser power in SERF comagnetometers.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Chemistry, Multidisciplinary
Martin Kunth, Leif Schroeder
Summary: The study simplifies the behavior of spin-spin relaxation rates in different chemical environments using hyperpolarized Xe-129 as a reporter ligand. It was found that even in a diamagnetic system, detection of analyte concentrations can be achieved through large Larmor frequency jumps. This approach provides a way to measure exchange rates even in systems where direct measurements are challenging.
Article
Physics, Multidisciplinary
Farzad Mahfouzi, Nicholas Kioussis
Summary: This study presents the phenomenon of charge and spin currents induced by acoustic phonons and analyzes the origin and properties of the pumped currents.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
X. Liu, P. Liu, H. C. Yuan, J. Y. Shi, H. L. Wang, S. H. Nie, F. Jin, Z. Zheng, X. Z. Yu, J. H. Zhao, H. B. Zhao, G. Lupke
Summary: Spin angular momentum transfer in magnetic bilayers offers the potential for ultrafast and low-loss operation in next-generation spintronic devices. In this study, field- and temperature-dependent measurements were conducted on the magnetization precessions in Co2FeAl/(Ga,Mn)As using time-resolved magneto-optical Kerr effect. The results indicate an enhanced dynamic exchange coupling between the two ferromagnetic layers due to reinforced spin pumping at resonance, as well as a primary contribution from the ferromagnetism in (Ga,Mn)As.
SCIENTIFIC REPORTS
(2022)
Article
Physics, Multidisciplinary
Junpei Zhang, Chuyi Huang, Zecong Qin, Fan Ye, Syed Mohd Amir, Ahmed Salman, Yuchen Dong, Long Tian, Zachary Nortis Buck, Wolfgang Kreuzpaintner, Matthew Musgrave, Xin Qi, Tianhao Wang, Xin Tong
Summary: This paper presents the performance of an in-situ spin-exchange optically pumped He-neutron spin filter system at the China Spallation Neutron Source (CSNS). The system achieved a He-3 polarization of over 74% at the beamline BL-20. Neutron transmission experiment results show a neutron polarization of >90% and an average transmission of 27% for 2.2A neutrons, maintained for 120 hours of beam time. This is the first in-situ hyperpolarized He-3 system incorporated on a neutron beamline in China and is expected to provide stable, wide-angle, and highly polarized neutrons for materials research and fundamental neutron physics at the CSNS.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2022)
Article
Materials Science, Multidisciplinary
Piotr Skalski, Olga Zadvorna, Deepak Venkateshvaran, Henning Sirringhaus
Summary: Organic spintronics is a thriving field, with organic semiconductors considered as potential alternatives to inorganic materials for spintronic applications. Recent research has shown that commonly used control experiments are insufficient to prove spin transport and can lead to incorrect interpretation of signals.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Yao Wei, Yueyang Zhai, Renjie Li, Sixun Liu, Wenfeng Fan, Wei Quan
Summary: This article establishes a model to quantitatively evaluate the polarization error in the output signal of a spin-exchange relaxation-free (SERF) co-magnetometer induced by transverse optical pumping (TOP). Based on this model, a novel fast measurement method for TOP is proposed, which utilizes steady-state response output signals and longitudinal polarization information. Furthermore, a method of suppressing TOP based on counter-propagating beam is suggested, effectively reducing the circular polarization-induced TOP by adjusting the phase retardation. The stability of the SERF co-magnetometer's outputs is improved, with a reduction in the coupling effect between probe beam power fluctuation and output signal bias.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Multidisciplinary Sciences
Daniel Keith, Yousun Chung, Ludwik Kranz, Brandur Thorgrimsson, Samuel K. Gorman, Michelle Y. Simmons
Summary: This research demonstrates an initialization and measurement technique based on voltage ramps, which enables high-fidelity electron spin readout at higher temperatures. This technique requires lower energy and offers practical benefits such as real-time dynamic feedback and minimal alignment procedures.
Article
Chemistry, Multidisciplinary
M. Grzeszczyk, S. Acharya, D. Pashov, Z. Chen, K. Vaklinova, M. van Schilfgaarde, K. Watanabe, T. Taniguchi, K. S. Novoselov, M. I. Katsnelson, M. Koperski
Summary: It is discovered that despite similar structural and magnetic configurations, the coupling between excitons and magnetization is qualitatively different in CrBr3 and CrI3 films. Through a combination of optical spin pumping experiments and state-of-the-art theory, it is concluded that the hole-magnetization coupling has the opposite sign in CrBr3 and CrI3, as well as between the ground and excited exciton state. Efficient spin pumping capabilities are demonstrated in CrBr3 driven by magnetization via spin-dependent absorption, and the different origins of the magnetic hysteresis in CrBr3 and CrI3 are unraveled.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Eirik Holm Fyhn, Jacob Linder
Summary: We theoretically study the effect of a rotating electric field on a diffusive nanowire and find an effect similar to spin pumping, resulting in a measurable spin-voltage along the axis of rotation.
Article
Multidisciplinary Sciences
Z. Q. Qiu
Summary: This commentary summarizes recent progress on spin pumping by ferromagnetic resonance in magnetic heterostructures, with a focus on the chirality dependence of the spin current.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Michael J. Dominguez, Hua-Wei Hsu, Vanessa Sih
Summary: Consecutive circularly polarized optical pulses generate and rotate electron spin polarization. Time- and magnetic-field-dependent optical pump-probe measurements on gallium arsenide show a variable Overhauser field growth that depends on the external magnetic field and laser wavelength. The time dependence of nuclear spin polarization can be attributed to the time-averaged electron spin polarization along the external magnetic field direction.
Article
Chemistry, Multidisciplinary
Christopher Nelson, Andreas B. Schmidt, Isaiah Adelabu, Shiraz Nantogma, Valerij G. Kiselev, Abubakar Abdurraheem, Henri de Maissin, Soeren Lehmkuhl, Stephan Appelt, Thomas Theis, Eduard Y. Chekmenev
Summary: The feasibility of Carbon-13 Radiofrequency (RF) Amplification by Stimulated Emission of Radiation (C-13 RASER) is demonstrated on a bolus of liquid hyperpolarized ethyl [1-C-13]acetate. The study successfully observed C-13 RASER signals and demonstrated its potential application on biomolecular carriers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Md Shahabuddin Alam, Xinlin Li, Drew O. O. Brittin, Saiful Islam, Pravas Deria, Eduard Y. Y. Chekmenev, Boyd M. M. Goodson
Summary: A novel phenomenon is described in which large antiphase o-H-2 signals are observed when using an intact heterogeneous catalyst constructed using a metal-organic framework (MOF), and this effect is qualitatively independent of substrate nature.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Analytical
Keilian MacCulloch, Austin Browning, Patrick TomHon, Soeren Lehmkuhl, Eduard Y. Chekmenev, Thomas Theis
Summary: Hyperpolarization modalities, particularly SABRE, are employed to enhance 15N polarization of nitrile-containing anticancer drugs. Optimal parameters, including temperature, magnetic field, and field profile, are fine-tuned for different substrates. Over 10% hyperpolarization and 280,000-fold signal enhancement are achieved for letrozole and anastrozole. Prolonged polarization storage and signal detection are enabled by the nitrile 15N sites.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
David O. Guarin, Sameer M. Joshi, Anna Samoilenko, Mohammad S. H. Kabir, Erin E. Hardy, Atsush M. Takahashi, Jan H. Ardenkjaer-Larsen, Eduard Y. Chekmenev, Yi-Fen Yen
Summary: We present the first report of dissolution Dynamic Nuclear Polarization (d-DNP) of [N-15(3)]metronidazole ([N-15(3)]MNZ). Metronidazole, a clinically approved antibiotic, shows potential as a hypoxia-sensing molecular probe using N-15 hyperpolarized (HP) nucleus. The d-DNP process using trityl radical achieves efficient hyperpolarization of [N-15(3)]MNZ with long-lasting signal and high polarization.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Boyd M. Goodson, Qingfeng Ge, Lichang Wang
Summary: In the past 20 years, there has been significant effort to advance the modular approach to teaching chemistry laboratory courses. This article presents the development and implementation of two modules for a second-semester physical chemistry laboratory course: an inquiry-based module on proteins and a project-based module on organic small molecules. These modules focus on specific molecular systems and allow students to choose and apply different methods to study them, based on each method's advantages and disadvantages. The main goals of the modules are to develop students' critical thinking skills, provide real-world applications for their knowledge, encourage them to emulate scientists, and inspire them to pursue research opportunities. The article provides details on how this modular approach has been implemented in teaching the second-semester physical chemistry laboratory over the past 11 years. Assessment results indicate that this two-level modular approach has achieved its goals and helped students choose research-based careers.
JOURNAL OF CHEMICAL EDUCATION
(2023)
Article
Chemistry, Physical
Mohammad S. H. Kabir, Sameer M. Joshi, Anna Samoilenko, Isaiah Adelabu, Shiraz Nantogma, Juri G. Gelovani, Boyd M. Goodson, Eduard Y. Chekmenev
Summary: Efficient hyperpolarization of [N-15(3)]metronidazole was achieved using the SABRE-SHEATH technique. The functionalization of [N-15(3)]metronidazole with a fluorine-19 moiety was also successful, resulting in efficient hyperpolarization of all three N-15 sites. The spin-relayed polarization transfer between N-15 and F-19 was found to be less efficient.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Andreas B. Schmidt, Isaiah Adelabu, Christopher Nelson, Shiraz Nantogma, Valerij G. Kiselev, Maxim Zaitsev, Abubakar Abdurraheem, Henri de Maissin, Matthew S. Rosen, Soren Lehmkuhl, Stephan Appelt, Thomas Theis, Eduard Y. Chekmenev
Summary: Conventional nuclear magnetic resonance (NMR) is used to detect chemical transformations by exciting and detecting the precessing spins of nuclear spin ensembles. In this study, we employ Radiofrequency Amplification by Stimulated Emission of Radiation (RASER) to detect chemical transformations without the need for external radio frequency pulses or background signals. We investigated the hydrolysis of hyperpolarized ethyl-[1-C-13]-acetate using both conventional NMR and C-13 RASER and observed a complete disappearance and delayed reappearance of the RASER signal without destroying the C-13 polarization.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Review
Radiology, Nuclear Medicine & Medical Imaging
Adrienne E. Campbell-Washburn, Kathryn E. Keenan, Peng Hu, John P. Mugler, Krishna S. Nayak, Andrew G. Webb, Johnes Obungoloch, Kevin N. Sheth, Juergen Hennig, Matthew S. Rosen, Najat Salameh, Daniel K. Sodickson, Joel M. Stein, Jose P. Marques, Orlando P. Simonetti
Summary: The first ISMRM Workshop on Low-Field MRI was held virtually in March 2022, discussing recent advancements in low field MRI technology and its clinical applications. With 368 registrants from 24 countries, the workshop included invited talks, abstract presentations, panel discussions, and live scanner demonstrations. The workshop emphasized the potential of low-field MRI in expanding MRI usage through cost reduction, portability, and ease of installation, as well as the challenges in overcoming SNR limitations and establishing clinical value.
MAGNETIC RESONANCE IN MEDICINE
(2023)
Review
Radiology, Nuclear Medicine & Medical Imaging
Frank G. Shellock, Matthew S. Rosen, Andrew Webb, W. Taylor Kimberly, Sunder Rajan, Aleksandar N. Nacev, John V. Crues
Summary: The standard of care for patients with implants is to determine the safety of scanning based on the field strength of the MRI scanner. However, facilities with scanners operating below 1.5T face challenges when encountering patients with implants, as scanning them is considered off-label. This monograph provides an overview of the safety issues related to passive implants and offers recommendations for managing patients with implants labeled MR Conditional at 1.5T and/or 3T on scanners operating below 1.5T.
JOURNAL OF MAGNETIC RESONANCE IMAGING
(2023)
Article
Optics
Lars Lohmann, Soeren Lehmkuhl, Simon Fleischer, Matthew S. Rosen, Eduard Y. Chekmenev, Thomas Theis, Alina Adams, Stephan Appelt
Summary: A nuclear-spin-based RASER is used to explore nonlinear interaction phenomena of nuclear spins coupled via virtual photons to a resonator. The experiment shows various nonlinear phenomena in the parahydrogen-pumped two-compartment proton RASER, including mode oscillations, frequency shifts, frequency combs, period doublings, and chaos. The mode separation in the RASER is precisely controlled by a magnetic field gradient to select the observed nonlinear phenomena.
Article
Chemistry, Physical
Austin Browning, Keilian Macculloch, Patrick TomHon, Iuliia Mandzhieva, Eduard Y. Chekmenev, Boyd M. Goodson, Soeren Lehmkuhl, Thomas Theis
Summary: Hyperpolarization of C-13-pyruvate via Signal Amplification By Reversible Exchange (SABRE) is an important recent discovery due to the simplicity of hyperpolarization and the relevance of pyruvate as a biomolecular probe. This study analyzes the [1,2-C-13(2)]pyruvate-SABRE spin system theoretically and experimentally, providing insights into spin state mixing, dynamics, and resulting spectra. The results are compared to systematic experiments, enhancing our understanding of the [1,2-C-13(2)]pyruvate-SABRE system.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Iuliia Mandzhieva, Isaiah Adelabu, Shiraz Nantogma, Eduard Y. Chekmenev, Thomas Theis
Summary: This study presents a new pulse sequence approach that allows the use of hyperpolarized MRI for molecular imaging of metabolic diseases on clinical MRI scanners. The approach transfers C-13 hyperpolarization to methyl protons for detection and is robust to magnetic field inhomogeneities.
