A Student at Hope College in the Preparatory School, R. H. Joldersma, Wrote a Report in the Student Publication, the Excelsiora, on the Death of Albertus C. Van Raalte

A student at Hope College in the Preparatory School, R. H. Joldersma, wrote a report in the student publication, the Excelsiora, on the death of Albertus C. Van Raalte. The student made much of the fact that Van Raalte\u27s death occurred on election day. When the death of V.R. was announced the school\u27s classes were dismissed for the rest of the week. Friday, the day of the funeral was beautiful. The funeral cortege was very long, seventy six carriage in addition to the formal line up of city council members, etc. After Dr. Crispell had closed with prayer, we left the Cemetery fully convinced that a great man had fallen. The death of V.R. must have made a great impression on the students. The account is hand written and consists of six pages.https://digitalcommons.hope.edu/vrp_1870s/1289/thumbnail.jp

Tunable sub-luminal propagation of narrowband x-ray pulses

Group velocity control is demonstrated for x-ray photons of 14.4 keV energy via a direct measurement of the temporal delay imposed on spectrally narrow x-ray pulses. Sub-luminal light propagation is achieved by inducing a steep positive linear dispersion in the optical response of ${}^{57}$Fe M\"ossbauer nuclei embedded in a thin film planar x-ray cavity. The direct detection of the temporal pulse delay is enabled by generating frequency-tunable spectrally narrow x-ray pulses from broadband pulsed synchrotron radiation. Our theoretical model is in good agreement with the experimental data.Comment: 8 pages, 4 figure

A. C. V. R. Gilmore, the Son of Rev. William and Christine Gilmore, Wrote a Letter to His Grandfather, Rev. Albertus C. Van Raalte, Expressing His Concern That Grandpa Was Ill

A. C. V. R. Gilmore, the son of Rev. William and Christine Gilmore, wrote a letter to his grandfather, Rev. Albertus C. Van Raalte, expressing his concern that grandpa was ill. The assigned date is uncertain. His parents lived in Amelia from 1869 to 1873. Even by 1873, it is doubtful that this child could have composed this letter in his own hand.https://digitalcommons.hope.edu/vrp_1870s/1007/thumbnail.jp

Universal time-evolution of a Rydberg lattice gas with perfect blockade

We investigate the dynamics of a strongly interacting spin system that is motivated by current experimental realizations of strongly interacting Rydberg gases in lattices. In particular we are interested in the temporal evolution of quantities such as the density of Rydberg atoms and density-density correlations when the system is initialized in a fully polarized state without Rydberg excitations. We show that in the thermodynamic limit the expectation values of these observables converge at least logarithmically to universal functions and outline a method to obtain these functions. We prove that a finite one-dimensional system follows this universal behavior up to a given time. The length of this universal time period depends on the actual system size. This shows that already the study of small systems allows to make precise predictions about the thermodynamic limit provided that the observation time is sufficiently short. We discuss this for various observables and for systems with different dimensions, interaction ranges and boundary conditions.Comment: 16 pages, 3 figure

Acoustically driven ferromagnetic resonance

Surface acoustic waves (SAW) in the GHz frequency range are exploited for the all-elastic excitation and detection of ferromagnetic resonance (FMR) in a ferromagnetic/ferroelectric (nickel/lithium niobate) hybrid device. We measure the SAW magneto-transmission at room temperature as a function of frequency, external magnetic field magnitude, and orientation. Our data are well described by a modified Landau-Lifshitz-Gilbert approach, in which a virtual, strain-induced tickle field drives the magnetization precession. This causes a distinct magnetic field orientation dependence of elastically driven FMR that we observe in both model and experiment.Comment: 4 page

Interferometric phase detection at x-ray energies via Fano resonance control

Modern x-ray light sources promise access to structure and dynamics of matter in largely unexplored spectral regions. However, the desired information is encoded in the light intensity and phase, whereas detectors register only the intensity. This phase problem is ubiquitous in crystallography and imaging, and impedes the exploration of quantum effects at x-ray energies. Here, we demonstrate phase-sensitive measurements characterizing the quantum state of a nuclear two-level system at hard x-ray energies. The nuclei are initially prepared in a superposition state. Subsequently, the relative phase of this superposition is interferometrically reconstructed from the emitted x-rays. Our results form a first step towards x-ray quantum state tomography, and provide new avenues for structure determination and precision metrology via x-ray Fano interference.Comment: 5 pages, 3 figures, plus supplementary informatio

Si-compatible candidates for high-K dielectrics with the Pbnm perovskite structure

We analyze both experimentally (where possible) and theoretically from first-principles the dielectric tensor components and crystal structure of five classes of Pbnm perovskites. All of these materials are believed to be stable on silicon and are therefore promising candidates for high-K dielectrics. We also analyze the structure of these materials with various simple models, decompose the lattice contribution to the dielectric tensor into force constant matrix eigenmode contributions, explore a peculiar correlation between structural and dielectric anisotropies in these compounds and give phonon frequencies and infrared activities of those modes that are infrared-active. We find that CaZrO_3, SrZrO_3, LaHoO_3, and LaYO_3 are among the most promising candidates for high-K dielectrics among the compounds we considered.Comment: 17 pages, 9 figures, 4 tables. Supplementary information: http://link.aps.org/supplemental/10.1103/PhysRevB.82.064101 or http://www.physics.rutgers.edu/~sinisa/highk/supp.pd