Hyperpolarized Molecules as Quantum Sensors

We develop hyperpolarization chemistry and quantum measurement methods that turn nuclear spins into sensitive probes of chemistry, biology, and fundamental physics.

Nuclear spins are extraordinary probes of molecular structure and dynamics, but their weak thermal polarization normally limits sensitivity. Our lab develops chemical and physical strategies that overcome this limitation by combining parahydrogen hyperpolarization, organometallic catalysis, optical pumping, zero- to ultralow-field (ZULF) NMR, and quantum magnetometry.

We are especially interested in molecules that do more than passively report their spectra. In our experiments, hyperpolarized molecules can act as spin amplifiers, self-sustained J-oscillators, and real-time reporters of chemical and biological transformations. This creates a bridge between physical chemistry, quantum sensing, catalysis, and biomedical magnetic resonance.

Molecular spin amplifiers

One of the central goals of our lab is to make molecular nuclear spins an active magnetic medium rather than passive NMR reporters. Hyperpolarization prepares dense ensembles of nuclear spins far from thermal equilibrium; when these spins respond to a weak magnetic field, their own magnetization can generate an additional field that amplifies the signal [1].

Hyperpolarized molecular nuclear spins can produce magnetic amplification in both linear and nonlinear regimes (i.e., under active feedback), extending amplification to scalar-coupled multi-spin molecules and motivating new approaches to quantum sensing, absolute magnetometry, and searches for weak spin-dependent interactions.

J-oscillators: coherent molecular clocks at zero field

NMR usually produces transient signals. We have developed a different mode of spectroscopy: quantum J-oscillators, where nuclear spin-spin couplings provide molecular fingerprints and programmable feedback sustains coherent oscillations.

In our 2026 Nature Communications work [2], zero-field J-oscillators used molecular J-couplings to produce phase-coherent continuous oscillations at sub-hertz to tens-of-hertz frequencies. In [¹⁵N]-acetonitrile, the oscillator achieved a 340 &mu Hz linewidth over 3600 seconds, more than two orders of magnitude narrower than conventional zero-field NMR under comparable conditions.

This turns zero-field NMR into a platform for precision molecular spectroscopy and nonlinear spin dynamics. By adjusting feedback phase and gain, we can selectively amplify different J-transitions, perform on-demand spectral editing, and explore dynamical regimes that connect magnetic resonance with the physics of lasers, masers, time crystals, and self-oscillating quantum systems [3].

Chemistry Behind Parahydrogen-based Hyperpolarization

Understanding organometallic catalysis

Parahydrogen-based hyperpolarization begins with chemistry. PHIP and SABRE rely on organometallic catalysts that convert the hidden spin order of parahydrogen into observable nuclear spin polarization. Understanding these catalysts — their activation pathways, hydride intermediates, ligand exchange, solvent effects, and long-term stability — is therefore central to building reliable hyperpolarized NMR and quantum-sensing experiments.

Our goal is to turn mechanistic understanding of catalytic hydrogenations into rational design: which catalyst, ligand, solvent, exchange regime, and magnetic-field condition will produce the right spin order for a given molecule and experiment?

Relayed hyperpolarization

Many important molecules do not bind directly to SABRE catalysts. Relayed hyperpolarization expands the molecular scope by passing spin order through exchangeable protons and then to heteronuclei such as ¹³C and ¹⁵N [4-5]. This gives access to metabolites, small biomolecules, and chemical reaction networks that would otherwise be difficult to observe with high sensitivity.

Toward low-field metabolic sensing

We aim to bring hyperpolarized magnetic resonance closer to living chemistry. By combining PHIP/SABRE, ZULF NMR, spin amplification, and kinetic modeling, we are developing approaches to monitor metabolic transformations such as pyruvate-to-lactate conversion and fumarate/malate/succinate-related pathways. Our long-term vision is real-time, low-field magnetic resonance for cell metabolism, catalysis, and biomedical chemistry.

Join the lab

Our work sits at the boundary of chemistry, physics, engineering, computation, and biology. Students may synthesize catalysts, build hyperpolarization and low-field NMR hardware, simulate spin dynamics, analyze real-time spectra, or develop biological assays. We are looking for curious people who want to learn across disciplines and build new magnetic-resonance tools from the molecules up.