Adam, ChristophOles, K.Romanczukiewicz, T.Wereszczynski, Andrzej2020-04-202020-04-202019Adam, C., Oles, K., Romanczukiewicz, T., & Wereszczynski, A. (2019). Spectral walls in soliton collisions. Physical Review Letters, 122(24). doi: 10.1103/physrevlett.122.2416010031-9007http://hdl.handle.net/10347/21574During defect-antidefect scattering, bound modes frequently disappear into the continuous spectrum before the defects themselves collide. This leads to a structural, nonperturbative change in the spectrum of small excitations. Sometimes the effect can be seen as a hard wall from which the defect can bounce off. We show the existence of these spectral walls and study their properties in the ϕ(4) model with Bogomol’nyi-Prasad-Sommerfield preserving impurity, where the spectral wall phenomenon can be isolated because the static force between the antikink and the impurity vanishes. We conclude that such spectral walls should surround all solitons possessing internal modeseng© The Author(s) 2019. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOIhttps://creativecommons.org/licenses/by/4.0/journal article10.1103/PhysRevLett.122.2416011079-7114open access