arXiv subjects

Urban Vernik

Publications and source records attributed to Urban Vernik.

4 recordsLinked to original sources

arXiv2026

High-precision ab initio calculations of nuclear binding energies: Tin isotopes from dripline to dripline

The location of the neutron drip line in tin isotopes has important consequences for our fundamental understanding of nuclear structure and nuclear forces as well as for astrophysical nucleosynthesis. Performing high-precision ab initio calculations of even-even tin isotopes from $N=50$ to $N=126$ based on chiral two- and three-nucleon interactions, the predicted drip-line location is found to be highly sensitive to the employed nuclear interactions and to exhibit tension with recent energy-density-functional predictions. On the neutron-deficient side, results are consistent with extrapolated two-neutron separation energies constrained by recent Penning-trap mass measurements.

nucl-th↗

arXiv2026

Ab initio calculations of nuclear charge radii across and beyond ${}^{132}$Sn: Putting chiral EFT nuclear interactions to the test

Charge radii are investigated along the Tin isotopic chain via ab initio Bogoliubov coupled cluster calculations at the singles and doubles level. In addition to the reproduction of absolute radii, the parabolic behavior of isotopic shifts between the N = 50 and N = 82 magic numbers and the kink through ${}^{132}$Sn are shown to provide stringent tests for state-of-the-art chiral effective field theory ($\chi$EFT) inter-nucleon interactions. Indeed, none of the employed fine-tuned interactions can capture all such key characteristics. Eventually, the pronounced sensitivity of the results to the employed Hamiltonian beyond ${}^{132}$Sn provides a unique playground to pin down critical attributes of $\chi$EFT inter-nucleon interactions in the future. This calls for measuring isotopic shifts both towards ${}^{100}$Sn and beyond ${}^{134}$Sn, as well as for performing high-accuracy ab initio calculations of mean-square radii in heavy open-shell nuclei by adding both triples corrections to the many-body wave function and the two-body charge density correction to the operator

nucl-th↗

arXiv2025

Exploring quark mass dependent three-nucleon forces in medium-mass nuclei

Recently, new quark mass dependent three-nucleon (3N) forces have been identified, whose contributions in nuclear matter exceed expectations of Weinberg power-counting arguments. In this work, we investigate the impact of the most dominant new interaction term, characterized by the coupling $F_2$, in ab initio calculations of medium-mass nuclei. For this, we combine the new $F_2$ interaction with established 3N interactions up to next-to-next-to-leading order (N$^2$LO) and next-to-next-to-next-to-leading order (N$^3$LO) in chiral effective field theory. We explore two fit strategies for the low-energy couplings. The first is based only on few-body observables, while the second also incorporates information from $^{16}$O. Generally, we find that the $F_2$ interaction has a significant impact on energies and radii, however mainly due to changes in the short-range couplings. Overall, we do not find systematic improvements in the reproduction of medium-mass nuclei when the additional $F_2$ interaction is included.

nucl-th↗

arXiv2022

Resonant phonon-magnon interactions in free-standing metal-ferromagnet multilayer structures

We analyze resonant magneto-elastic interactions between standing perpendicular spin wave modes (exchange magnons) and longitudinal acoustic phonon modes in free-standing hybrid metal-ferromagnet bilayer and trilayer structures. Whereas the ferromagnetic layer acts as a magnetic cavity, all metal layers control the frequencies and eigenmodes of acoustic vibrations. The here proposed design allows for achieving and tuning the spectral and spatial modes overlap between phonons and magnons that results in their strong resonant interaction. Realistic simulations for gold-nickel multilayers show that sweeping the external magnetic field should allow for observing resonantly enhanced interactions between individual magnon and phonon modes in a broad range of frequencies spanning from tens of GHz up to several hundreds of GHz, which can be finely tuned through the multilayer design. Our results would enable the systematic study and the deep understanding of resonantly enhanced magneto-elastic coupling between individual phonon and magnon modes up to frequencies of great contemporary fundamental and applied interest.

cond-mat.mtrl-sci↗