A. Ciobanu | Searcharxiv

arXiv2022

Topological waves in the continuum in magnetized graphene devices

We show that topological waves at the interface between two magnetic domains in a graphene device are possible. First, we consider the case of a linear relation between the applied gate voltage and local density in the channel and, secondly, we investigate the effect of non-local Coulomb interactions. We obtain two distinct edge modes for each interaction type: a Yanai mode with rotational flow and dispersion relation that extends to infinite wave-number, and a Kelvin mode with purely longitudinal flow and bound dispersion relation. The scattering matrix concept is applied to verify the infinite frequency regime of the spectrum, and the bulk-edge correspondence principle is satisfied if one takes into account the Kelvin modes that merge with an imaginary cut of the bulk band.

cond-mat.mes-hall↗

arXiv2020

Neutron Star Extreme Matter Observatory: A kilohertz-band gravitational-wave detector in the global network

Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly-rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2-4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a neutron star extreme matter observatory (NEMO): a gravitational-wave interferometer optimized to study nuclear physics with merging neutron stars. The concept uses high circulating laser power, quantum squeezing and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above one kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year, and potentially allows for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.

astro-ph.HE↗