A Flux-Tunable Discrete Angular Filter |
| T.M. Lawriea, b, O.M. Brownc
aCentre for Material Research and Innovation, Department of Physics and Astronomy, University of Exeter bSchool of Mathematical Sciences, University of Nottingham cSchool of Mathematics, University of Bristol |
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| Recent work by Lawrie et al. Phys. Rev. Research 7, 023209 (2025) introduced a non-diffracting resonant angular filter on a network of thin channels (modelled using quantum graph theory) that exhibits unit transmission of acoustic waves at a discrete, symmetry-paired set of incidence angles. This set is determined solely by the graph topology, while transmission at all other angles is strictly forbidden. In the present work, we study the same filtering geometry for waves governed by the magnetic Schrödinger equation rather than the classical wave equation. Using a phase shift induced by non-reciprocal wave propagation due to the presence of the magnetic potential, as well as tuning δ-type vertex boundary conditions, we make the previously topology-fixed discrete pass directions continuously tunable. Both the transmission angle and the transmission coefficient become control parameters. The resulting flux-tunable angular filtering device replaces the topology-constrained passbands with a programmable steering device, broadening the scope for wave-filter and beam-shaping applications. |
DOI:10.12693/APhysPolA.148.S25 topics: quantum graphs, scattering, Aharonov-Bohm, wave filter |