collaborators

6 papers

cond-mat.mes-hall2026

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

Danyu Shu, Ryotaro Sano, Ai Yamakage +2

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…

nucl-th2026

Thermal Spin Polarization Driven by Nuclear Spin-Orbit Coupling in Neutron Star Pasta

Hiroyuki Tajima, Yuta Sekino, Hiroshi Funaki +3

We discuss anomalous spin polarization on the surface of nuclear pasta in a neutron star, driven by a nuclear spin-orbit interaction. We present an effective two-band model of surf…

cond-mat.mes-hall2026

Gyromagnetic Quantum Friction in Rayleigh Vorticity Baths

Mamoru Matsuo, Ryotaro Sano, Ai Yamakage +2

We identify an intrinsic zero-temperature relaxation channel for near-surface spins gyromagnetically coupled to Rayleigh-wave vorticity. This surface-mode contribution requires no…

cond-mat.mes-hall2025

Charge and Valley Hydrodynamics in the Quantum Hall Regime of Gapped Graphene

Danyu Shu, Hiroshi Funaki, Ai Yamakage +2

We develop a unified viscous hydrodynamics for charge and valley transport in gapped graphene in the quantum Hall regime. We redefine Hall viscosity as a response to static electri…

astro-ph.HE2025

Gyromagnetic Angular Momentum Interconversion in Neutron Stars

Hiroshi Funaki, Yuta Sekino, Hiroyuki Tajima +3

We propose a novel mechanism for angular momentum (AM) exchange between the crust and core of a neutron star (NS) via the gyromagnetic effect. Using extended hydrodynamics, we mode…

cond-mat.mes-hall2025

Directional propagation of quantum Hall viscous fluid by nano-structural engineering

Hiroshi Funaki, Ai Yamakage, Ryotaro Sano +1

We present a microscopic theory of the viscous electron fluid in the quantum Hall state based on the nonequilibrium Green's function method and the von Neumann lattice representati…