Classification of ground states and normal modes for phase-frustrated multicomponent superconductors
2013 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 88, no 21, 214507- p.Article in journal (Refereed) Published
We classify ground states and normal modes for n-component superconductors with frustrated intercomponent Josephson couplings, focusing on n=4. The results should be relevant not only to multiband superconductors, but also to Josephson-coupled multilayers and Josephson-junction arrays. It was recently discussed that three-component superconductors can break time-reversal symmetry as a consequence of phase frustration. We discuss how to classify frustrated superconductors with an arbitrary number of components. Although already for the four-component case there are a large number of different combinations of phase-locking and phase-antilocking Josephson couplings, we establish that there are a much smaller number of equivalence classes where properties of frustrated multicomponent superconductors can be mapped to each other. This classification is related to the graph-theoretical concept of Seidel switching. Numerically, we calculate ground states, normal modes, and characteristic length scales for the four-component case. We report conditions of appearance of new accidental continuous ground-state degeneracies.
Place, publisher, year, edition, pages
2013. Vol. 88, no 21, 214507- p.
2-Band Superconductors, Number
IdentifiersURN: urn:nbn:se:kth:diva-139452DOI: 10.1103/PhysRevB.88.214507ISI: 000328676900006ScopusID: 2-s2.0-84890612513OAI: oai:DiVA.org:kth-139452DiVA: diva2:687664
FunderKnut and Alice Wallenberg FoundationSwedish Research Council
QC 201401152014-01-152014-01-132014-01-21Bibliographically approved