@article{yu_yapa_konig_2024, title={Complex scaling in finite volume}, volume={109}, ISSN={["2469-9993"]}, url={https://doi.org/10.1103/PhysRevC.109.014316}, DOI={10.1103/PhysRevC.109.014316}, abstractNote={Quantum resonances, i.e., metastable states with a finite lifetime, play an important role in nuclear physics and other domains. Describing this phenomenon theoretically is generally a challenging task. In this work, we combine two established techniques to address this challenge. Complex scaling makes it possible to calculate resonances with bound-state-like methods. Finite-volume simulations exploit the fact that the infinite-volume properties of quantum systems are encoded in how discrete energy levels change as one varies the size of the volume. We apply complex scaling to systems in finite periodic boxes and derive the volume dependence of states in this scenario, demonstrating with explicit examples how one can use these relations to infer infinite-volume resonance energies and lifetimes.}, number={1}, journal={PHYSICAL REVIEW C}, author={Yu, Hang and Yapa, Nuwan and Konig, Sebastian}, year={2024}, month={Jan} }
 @article{yu_koenig_lee_2023, title={Charged-Particle Bound States in Periodic Boxes}, volume={131}, ISSN={["1079-7114"]}, url={https://doi.org/10.1103/PhysRevLett.131.212502}, DOI={10.1103/PhysRevLett.131.212502}, abstractNote={We consider the binding energy of a two-body system with a repulsive Coulomb interaction in a finite periodic volume. We define the finite-volume Coulomb potential as the usual Coulomb potential, except that the distance is defined as the shortest separation between the two bodies in the periodic volume. We investigate this problem in one and three-dimensional periodic boxes and derive the asymptotic behavior of the volume dependence for bound states with zero angular momentum in terms of Whittaker functions. We benchmark our results against numerical calculations and show how the method can be used to extract asymptotic normalization coefficients for charged-particle bound states. The results we derive here have immediate applications for calculations of atomic nuclei in finite periodic volumes for the case where the leading finite-volume correction is associated with two charged clusters.}, number={21}, journal={PHYSICAL REVIEW LETTERS}, author={Yu, Hang and Koenig, Sebastian and Lee, Dean}, year={2023}, month={Nov} }