物理学
The advancements in highly sensitive and powerful radio telescopes, including the Square Kilometre Array Observatory (SKAO) and its precursors, MeerKAT, ASKAP, MWA, and HERA, will enable us to create the deepest radio images of the sky.…
The equal-charge branch of supersymmetric rotating AdS$_5$ black holes has $Q_1=Q_2=Q_3$. The corresponding microcanonical sector of the $\mathcal{N}=4$ superconformal index is obtained by projecting to equal charges, or equivalently by…
Circularly symmetric diffuse radio sources represent a recently recognized and rare class of extragalactic synchrotron-emitting structures whose physical origin remains uncertain. The currently known population is small, and the limited…
Several observational and theoretical studies have suggested that the observed arm-length asymmetries in extragalactic radio sources are primarily driven by interactions between radio jets and an inhomogeneous ambient medium, although…
We present numerical three body simulations of a primordial black hole (PBH) encounter with the TOI 2796 system, which hosts a hot Jupiter. Over 100 days, we identify three outcomes: (i) ejection of the planet; (ii) a bound triple system (a…
We show through theory and numerical experiments that a straightforward calculation of entropy production on short molecular dynamics trajectories allows estimating free-energy barriers and identifying optimal reaction coordinates of…
Pulse profile modeling has proven to be a powerful technique for determining the mass and radius of neutron stars. To date, this method has been applied to a handful of millisecond pulsars observed by the Neutron Star Interior Composition…
We study the nonlinear Hall effect in Floquet-driven monolayer \(1T'\)-MoS\(_2\), a low-symmetry quantum spin Hall material whose tilted Dirac bands sustain an intrinsic Berry-curvature dipole without the need for strain or trigonal…
This article provides a self-contained bridge between classical vortex dynamics and the relativistic, subatomic domain of the Quark-Gluon Plasma (QGP) produced in ultra-relativistic heavy-ion collisions. While the QGP is widely studied for…
To probe the interplay between dark matter (DM) and non-linear electrodynamics (NED), we consider the Bardeen black hole (BH) surrounded by perfect fluid dark matter (PFDM). We first compute the effective potential governing the particle…
We investigate the effects of isovalent Sb substitution at the As site in fluorine-doped PrFeAs1-xSbxO0.7F0.3 (x = 0 to 1.0) through structural, Raman spectroscopy, density functional theory (DFT), transport, magnetotransport, and magnetic…
Antiferromagnets offer a promising route toward robust spintronic devices because of their compensated magnetic order and exchange-enhanced spin dynamics. Here, we demonstrate a spin-orbit torque (SOT)-driven antiferromagnetic oscillator…
A central challenge in flat-band engineering is suppressing kinetic energy without sacrificing Berry curvature. We show that a double-helix skyrmion crystal (DHSKX)--two sublattice-resolved skyrmion textures locked at opposite helicities,…
We present correlated-electron calculations of optical spin-singlet and triplet-triplet multiexciton states in three- and four-unit pentacene oligomers as microscopic models for polypentacene. The calculations use the Pariser-Parr-Pople…
Gold nanonecklace networks are promising platforms for single-electron switching, chemical sensing, and biogating devices because of their nonlinear current--voltage ($I$--$V$) characteristics arising from collective Coulomb-blockade…
Supra-arcade downflows (SADs) are sunward-traveling features routinely observed in hot fan structures above magnetic loop arcades during eruptive solar flares. We manually compiled a catalog (SADCat) of 178 SAD-productive flares imaged by…
Barium titanate-on-insulator (BTOI) is a compelling material for high-speed integrated photonic modulators due to its large Pockels coefficient (r42 > 1200 pm/V in bulk), which allows for the miniaturization of modulators while maintaining…
Blazars are among the most extreme classes of active galactic nuclei. They are powered by relativistic jets, but the way in which the jet energy is dissipated is still unclear. The flat radio spectrum and the core-shift effect trace the…
This report summarizes the research outcomes achieved by the research group at Hokkaido University under the funding program "Innovative Information and Communications Technology Research and Development (Commissioned Research)" of the…
We study the Josephson effects in the spin-triplet superconductor/altermagnet/spin-triplet superconductor junctions using the Green's function method. It is found that the current-phase difference relationships in the junctions strongly…