Quantum Control and Sensing by Spin Cooling
To reveal “invisible” NMR signal of surfaces, active sites, and functional species in catalysis, molecular recognition and quantum materials using out of the box tools.
Quantum Resonance Sensing of Molecular Activity in Water
SpinQubes
To transform the study of molecular and soft materials structure, dynamics and interactions using innovative magnetic resonance spectroscopy tools and through the design of coupled electron and nuclear spin systems as amplifiers and sensors.
Spins as Nature’s Quantum Reporters
The Han Lab pushes the frontiers of magnetic resonance and quantum information science with the goal of “seeing” chemical and biological building blocks and processes at the quantum limit. The two main themes of the Han Lab over the past 20 years have been spins and water. Electron and nuclear spins are the ultimate quantum reporters and contrast agents for biochemical processes and chemical building blocks. Advanced magnetic resonance sensing, control over the spatial organization of electron and nuclear spin clusters, and dual electron-nuclear magnetic resonance techniques have contributed to uncovering new design rules for molecular recognition, as well as the surface structuring, shaping, and ordering of biological water.
Recently, we have begun to ask the ultimate question: do quantum phenomena direct and control biological and chemical processes? The answer is yes, but high-quality experimental validations are key to qualifying the context and boundaries of these answers. Recent breakthrough developments by the Han Lab offer one-of-a-kind experimental tools that allow us to gain control over the initialization and manipulation of quantum spin states via spin cooling at high magnetic fields.
This development effort requires interdisciplinary research tools, including instrument development to combine electron and nuclear magnetic resonance with optical excitation and detection, the design of precisely tuned electron and nuclear spin qubits, spin dynamics simulations, and studies of the dynamics and thermodynamics of solvation to control biomolecular activity and assembly.
We are motivated by the power of “Seeing is Believing.” New tools for visualizing molecular interactions and materials interfaces—previously “invisible”—have fundamentally transformed our ability to discover solutions and ask new questions. The next frontier of visualization will be quantum microscopy that relies on spins as quantum reporters to deliver molecular insights that conventional microscopy cannot.
Areas Of Research
Research in the Han Lab develops novel tools to exploit spins as quantum reporters with unprecedented sensitivity and information content and as biological qubits with spin state control. Our core interest lies in advancing spin-based quantum information science, solvation science, and the molecular basis of signal transduction.
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Chromophore Receptors as Biological Qubits
To reveal long-standing questions on the structure and dynamics of water on proteins, membranes to catalyst support surfaces.
Water Directed Protein Fibrils and Tunable Hydrogels
To understand, control and engineer protein aggregation pathways, protein surface activity to protein liquid-liquid phase separation.
Publications
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DEER of Singly Labelled Proteins to Evaluate Supramolecular Packing of Amyloid Fibrils
K. Tsay, A. Equbal, Y. Li, T. Tsui, S. Han, Y. Fichou eLife 2026, 15, RP111093
https://doi.org/10.7554/eLife.111093.1. PMID: 42239336. PMCID: PMC13228447.
The formation of protein amyloid fibrils in the brain is a hallmark of various neurodegenerative diseases, including Alzheimer diseases and Parkinson diseases. Amyloid fibrils are highly ordered aggregates in which proteins folded in two-dimensional layers stack along one axis to form elongated linear assemblies. The specific conformations adopted by the proteins within each layer of the amyloid correlates with the pathology. Furthermore, their spreading and templating competency relies on strict in register packing of the folded proteins along the fibril growing axis. There is a need for tools to characterize not only the protein fold across the fibril cross section but also the spatial ordering of the proteins stacked along the amyloid fibril axis. We present an approach based on double electron electron resonance spectroscopy (DEER) using singly labelled tau protein assembled in amyloid fibrils that can deliver an apparent dimensionality of the supramolecular organization of tau fibrils. The parameters of the DEER background function can be used to assess the amyloid core location and packing order, and track time-resolved formation of aggregation intermediates. Showcasing the method on tau, we demonstrate that heparin-induced tau fibrils are mispacked while seeded aggregation can template amyloid fibrils with a higher packing order. This study benchmarks a new method that will provide critical structural insights into amyloid assemblies.
Pump-Induced Dipolar Order to Evaluate Electron Spin Coupling Networks and Many-Body Effects
J. Straub, A. Equbal, Q. Stern, S. Han. ChemRxiv 2025
Networks of coupled electron spins are integral to applications in dynamic nuclear polarization, quantum information science, and materials properties emerging from many-body correlations. A minimal condition for electron spin entanglement or many- body spin correlations is dipolar order, yet techniques for creating and characterizing electron dipolar order of paramagnetic species are not broadly available. Here, we generate pump-induced dipolar order between P1 centers in powdered diamond samples and probe its formation by ELDOR (ELectron DOuble Resonance) and OOP-ESEEM (Out-Of-Phase Electron Spin Echo Envelope Modulation). ELDOR experiments on P1 centers show electron spin hyperpolarization which we attribute to the generation of dipolar order and subsequent conversion to Zeeman order. Pump-initialized OOP- ESEEM directly detects P1 dipolar order, with simulations confirming the experimental signatures originate from a heterogeneous network of coupled P1 centers. These results establish new approaches for monitoring dipolar order formation and probing materials’ potential for many-body effects.
Protein-Like Polymer for Inhibition of Tau Fibril Propagation in Human-Derived Models of Neurodegeneration
A. P. Longhini, M. Fattah, J. Sala-Jarque, A. DuBose, E. K. Rivera, O. R. Sclafani, J. Zhou, J. E. Anatot, M. P. Thompson, M. T. Unger, E. R. Beckett, C. Fagan, D. Nakamura, R. I. Morimoto, S. Han, B. Qiao, N. C. Gianneschi, K. S. Kosik. bioRxiv 2026.05.17.725757
The misfolding, aggregation, and spread of tau protein fibrils underlie tauopathies, a diverse class of neurodegenerative diseases for which effective treatments remain elusive. Among these are corticobasal dementia (CBD) and progressive supranuclear palsy (PSP), canonical examples of 4-repeat (4R) tauopathies characterized by tau isoforms exclusively with four microtubule-binding repeat domains. We target this 4R tau isoform-specific mechanism by focusing on misfolded tau’s distinctive stem-loop-stem structural motif formed by the junction of the 4R-defining alternatively spliced exon and the adjacent constitutive exon. A synthetic peptide based on this stem-loop-stem sequence can induce aggregation and spread in an isoform-specific manner. Here, we develop a protein-like polymer (PLP) in which multiple copies of this synthetic peptide form a brush-like structure capable of preventing tau aggregation by binding and capping fibril ends in vitro, in human brain organoids, and in cellular models with an EC50 of 105 ± 14 nM. PLPs demonstrate robust activity against fibrils derived from CBD and PSP patient brains and a PS19 mouse tauopathy model. Previous tau-targeted treatments have primarily focused on broad tau clearance, aggregation inhibition, or microtubule stabilization, often lacking isoform specificity and precision. In contrast, this approach targets the 4R tau isoform’s unique structural motif, offering a tailored therapeutic intervention for diseases like CBD and PSP. Supported by prior studies showing blood-brain barrier penetrance and safety profiles, this tau-binding PLP offers a promising translational path toward clinical applications in tauopathy treatment.
Recent News
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Wishing Everyone a Wonderful 25′ Holiday Season from Han Lab!
December 23, 2025
Three Defenses in the Festive Season: Congratulations to Our Newest PhDs
December 13, 2025
Interested in joining the Han research group? Reach us at han-ofc@northwestern.edu
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