Showing 53 results for Author: Daniel M. Pajerowski
Aug, 2026
Journal
Magnons in ferromagnets possess spin angular momentum defined by right-handed precession of the moment around the magnetization direction. In antiferromagnets with no net magnetization, left- and right-handed magnons are degenerate in the absence of an applied field. Ferrimagnets possess uncompensated magnetic sublattices, which should natively possess right- and left-hand…
Aug, 2026
Journal
Methods of elucidating the mechanisms of fast-ion conduction in solid-state materials are pivotal for advancements in energy technologies such as batteries, fuel cells, sensors, and supercapacitors. In this study, we examine the ionic conduction pathways in single crystal SrCl2, which is a fast-ion conductor above 900 K, using four-dimensional quasielastic neutron scatter…
Aug, 2026
Journal
Supersolid phases are quantum-entangled states of matter exhibiting the dual characteristics of superfluidity and solidity. Theory predicts that hard-core bosons on a triangular lattice can form such phases at half filling and near complete filling. Leveraging an exact mapping between bosons and spin-1/2 degrees of freedom, here we show that these phases are realized in th…
Apr, 2026
Journal
A codimension-two spiral spin liquid is a correlated paramagnetic state with one-dimensional ground state degeneracy hosted within a three-dimensional lattice. Here, via neutron scattering experiments and numerical simulations, we establish the existence of a codimension-two spiral spin liquid in the effective honeycomb-lattice compound Cs3Fe2Cl9, which demonstrates an a…
Feb, 2026
Journal
We investigate the magnetic behavior of the 6𝐻-perovskite dimer lattice Ba3Zn1−𝑥Ca𝑥Ru2O9 using analytical theory, density functional theory, inelastic neutron scattering, and modeling of historical magnetization and neutron-scattering data. A dimer mean-field theory built upon classical Luttinger–Tisza analysis generates a phase diagram revealing a transition from a n…
Dec, 2025
Journal
Bismuth exhibits a Peierls distortion away from a simple cubic structure, reflecting both an anharmonic potential energy surface and electron-phonon coupling in a semimetal. It has attracted considerable interest in studies of low-temperature thermal transport, thermoelectrics, and optical excitation of coherent phonon. Yet, the temperature-dependence of phonons in bismuth…
Dec, 2025
Journal
We derive a renormalized classical spin (RCS) theory for 𝑆>1/2 quantum magnets by constraining a generalized classical theory that includes all multipolar fluctuations to a reduced CP1 phase space of dipolar SU(2) coherent states. When the spin Hamiltonian ˆℋ(𝑆) is linear in the spin operators ˆ𝑺𝑗 for each lattice site 𝑗, the RCS Hamiltonian ˜ℋcl coincides with the usual…
Nov, 2025
Journal
The advent of higher flux neutron sources has made the use of sample changers appropriate across the instrument suites at neutron scattering facilities. We examine the efficiency, design, and operation of two sample changers used at the thermal chopper spectrometers at the Spallation Neutron Source. We also present case studies of sample holders designed to accommodate mul…
Jul, 2025
Journal
Conventional wisdom dictates that quantum effects become unimportant at high temperatures. In magnets, when the thermal energy exceeds interactions between atomic magnetic moments, the moments are usually uncorrelated, and classical paramagnetic behavior is observed. This thermal decoherence of quantum spin behaviors is a major hindrance to quantum information applications…
Jun, 2025
Journal
Metal halide perovskites (MHPs) have emerged as highly promising materials for optoelectronic applications, with all-inorganic MHPs presenting enhanced stability compared to their hybrid counterparts. Here, we investigate the atomic dynamics and structural fluctuations in single crystals of CsSnBr3 and CsPbBr3 through systematic inelastic neutron scattering (INS) measure…
May, 2025
Journal
This paper studies the topological and magnetic properties of a noncollinear spin state on a honeycomb lattice that evolves from coplanar to ferromagnetic with a magnetic field applied along the z axis. The coplanar state is stabilized by nearest-neighbor ferromagnetic interactions, single-ion anisotropy along z, and DzyaloshinskiiMoriya interactions between next-nearest-n…