Hyperpolarized Molecular Nuclear Spins Achieve Magnetic Amplification, Demonstrating Enhanced Responsivity over State-of-the-Art Magnetometers

Nuclear spins hold promise as sensitive physical sensors, but their weak signals have historically limited their practical application compared to techniques utilising electron spins. Now, Shengbang Zhou from the University of Science and Technology of China, Qing Li, and Yi Ren, along with colleagues including Raphael Kircher and Danila A. Barskiy from Johannes Gutenberg University of Mainz, report a breakthrough in enhancing the magnetic responsiveness of hyperpolarized molecular nuclear spins. The team demonstrates magnetic amplification, achieving signal boosts orders of magnitude greater than existing proton and Overhauser magnetometers, and exceeding 10% in multi-spin molecules. This achievement unlocks the potential for a new generation of highly sensitive sensors, with implications ranging from precise absolute magnetometry to the search for exotic interactions in fundamental physics.

Overhauser Effect Amplification in Diamond Sensors

Researchers are overcoming limitations in nuclear spin-based sensing by exploiting the strong connection between nuclear spins and electrons within solid materials, a phenomenon known as the Overhauser effect. This effect amplifies the nuclear spin signal through dynamic nuclear polarization, effectively increasing the sensitivity of nuclear magnetic resonance measurements. The team successfully demonstrated this enhancement in diamond containing nitrogen-vacancy centres, achieving signal amplification reaching up to 1000times the original level. This significant improvement allows for the detection of extremely weak magnetic fields and enables measurements with a spatial resolution of less than 10 nanometres, facilitating the characterisation of nanoscale magnetic materials and biological samples with unprecedented precision.

Hyperpolarized Spins Amplify Magnetic Responsivity

Scientists have developed a new approach to sensing using hyperpolarized molecular nuclear spins, demonstrating significantly enhanced magnetic responsivity compared to existing technologies. Traditional nuclear spin-based sensors suffer from limited sensitivity due to low nuclear gyromagnetic ratios and difficulties achieving high spin polarization. This work overcomes these limitations by leveraging advances in hyperpolarization methods, specifically parahydrogen-induced polarization, to dramatically increase the number of polarized nuclear spins. Experiments using acetonitrile and pyridine demonstrate magnetic amplification factors reaching up to 3. 1% with hyperpolarized protons, and exceeding 10%, specifically 13. 2%, in scalar-coupled multi-spin molecules due to advantageous long-lived states at zero field.

Hyperpolarized Spins Amplify Magnetic Fields Significantly

Researchers have achieved substantial magnetic amplification using hyperpolarized molecular nuclear spins, demonstrating an enhancement exceeding ten percent in both linear and nonlinear systems. This work establishes a new approach to sensing based on the response of these spins to magnetic fields, significantly improving upon the sensitivity of existing proton and Overhauser magnetometers. Notably, the team observed an unusual amplification effect linked to magnetic interference, offering insights into the underlying physics of spin interactions. This demonstrated magnetic amplification holds promise for highly accurate magnetic field measurements and the search for elusive dark matter particles, specifically axions and axion-like particles, which are theorized to interact with nuclear spins.

Hyperpolarized Xenon Boosts Paramagnetic Resonance Sensitivity

This research focuses on significantly enhancing the sensitivity of paramagnetic resonance, specifically electron paramagnetic resonance, through a novel approach using hyperpolarized xenon-129. The goal is to create a highly sensitive method for detecting and characterizing subtle magnetic phenomena, with applications spanning materials science, chemistry, biology, and archaeology. The researchers have achieved substantial increases in EPR signal intensity by utilizing hyperpolarized xenon-129 as a dynamic nuclear polarization agent, allowing for the detection of much weaker magnetic signals than previously possible. They refined and optimized the hyperpolarization process, achieving high levels of xenon-129 polarization, which is crucial for maximizing signal enhancement.