Divergence-free interpolation of tangential vector fields via matrix-valued kernels

Kavli Affiliate: Biao Huang | Summary:We develop and analyze a family of divergence-free kernel interpolation methods for tangential vector fields on the unit sphere. Starting from scalar radial kernels in Euclidean space, we construct tangent-valued, surface divergence-free matrix kernels without repeatedly applying surface differential operators. The construction separates the geometric enforcement of the divergence-free constraint […]


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Particle-Vortex Duality of Hydrodynamics

Kavli Affiliate: Matthew Fisher | Summary:Equipped with the recently recognized symmetry structure of mixed states of matter and "strong-weak spontaneous symmetry breaking" (SW-SSB), we develop a quantum particle-vortex duality of emergent model-F and model-A hydrodynamics of 2d boson/rotor systems. This duality relation demonstrates that classical hydrodynamics of 2d bosons can be described in terms of […]


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Ferromagnetic transition in a chiral spin chain

Kavli Affiliate: Leon Balents | Summary:We study the zero-temperature properties of a spin-$1/2$ Heisenberg chain with an additional three-site chiral term of strength $g$. The model is known to be integrable and previous work using Bethe ansatz has identified a phase transition from the usual critical state for $g< g_c = 2/π$ to a chiral […]


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Programmable Spin Conversion in Gradient Quantum Matter

Kavli Affiliate: Mamoru Matsuo | Summary:We propose programmable spin conversion in ultracold gases as gradient quantum matter, whose spin-dependent self-energy varies in space. Quantum kinetic theory shows that a dissipative self-energy curvature turns a force-driven scalar anisotropy into a spin source with mixed longitudinal-transverse momentum parity. Spin-resolved time-of-flight imaging can reveal a transverse spin texture […]


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Efficient Image Registration for Ultrasound Localization Microscopy by Obtaining Gradients via Integration Across Iterations

Kavli Affiliate: Biao Huang | Summary:Tissue motion correction through image registration is essential for ultrasound localization microscopy (ULM). Parametric image registration is commonly formulated as an optimization problem where motion parameters are iteratively updated to maximize image similarity, and used optimization algorithms typically rely on gradient information, the explicit evaluation of which can become computationally […]


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From Topological Order to Mixed-State Phases: A Ground-State Probe of Fractionalized Excitations

Kavli Affiliate: Shenghan Jiang | Summary:How do we detect topological phases from a single ground state? Entanglement entropy and spectrum have long been the standard tools — but the reduced density matrix (RDM) itself contains far more information. We show that the RDM of a 2D topologically ordered system, expressed at the entanglement cut, realizes […]


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From Topological Order to Mixed-State Phases: A Ground-State Probe of Fractionalized Excitations

Kavli Affiliate: Shenghan Jiang | Summary:How do we detect topological phases from a single ground state? Entanglement entropy and spectrum have long been the standard tools — but the reduced density matrix (RDM) itself contains far more information. We show that the RDM of a 2D topologically ordered system, expressed at the entanglement cut, realizes […]


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Microscopic derivation of the microstretch theory for carbon nanotubes

Kavli Affiliate: Mamoru Matsuo | Summary:Twisted carbon nanotubes support phonons involving not only torsion, naturally associated with microrotation, but also radial breathing, which requires a scalar stretch degree of freedom. We derive an effective microstretch theory for these modes starting from nonlinear elasticity on a cylindrical surface. By linearizing the equation of motion around a […]


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Quantum Geometric Origin of Hall Viscosity and Nonlocal Hall Conductivity in Lattice Bands

Kavli Affiliate: Mamoru Matsuo | Summary:We show that Hall viscosity in lattice bands is governed by a band-projected electric quadrupole encoded within the quantum geometry: Berry curvature sets the projected-coordinate algebra, while the quantum metric determines the quadrupolar spread of a wave packet. The same structure enters the quadratic wave-vector coefficient of the nonlocal Hall […]


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Reconstructing 3D Neural Hemodynamics using Sparse Ultrasound Localization Microscopy Data

Kavli Affiliate: Biao Huang | Summary:Ultrasound Localization Microscopy (ULM) has presented great potential in functional imaging, benefiting from its ability to reconstruct deep microvasculature. However, the hemodynamic reconstruction is compromised by sparsity in the ULM data, as a limited number of MB tracks cannot sample the complete speed profile in one vessel. Here, we propose […]


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