Work

Contact points open wide band gaps in all two-dimensional Bravais lattices

Year: 2026

Type: article

Abstract: The propagation of waves in crystals is known to be strongly affected by the choice and the spatial distribution of inclusions in a matrix. We argue herewith that in-contact, impermeable inclusions lead to extremely wide band gaps for all 2D Bravais lattices. Contact points entail constrictions that efficiently slow wave propagation and lead to strongly flattened bands. A numerical demonstration is provided for a generic Helmholtz equation that is applicable to electromagnetic, acoustic, elastic, or water waves alike. Experiments conducted on square and hexagonal photonic crystals composed of touching copper tubes reveal that waves of certain radio frequencies quite remarkably traverse the minute gaps within the metallic framework, thereby confirming the theoretical predictions, including the presence of deeply subwavelength Bragg band gaps.

Source: Physical review. B./Physical review. B

DOI: 10.1103/9ql7-t9rh

Authors: David Röhlig, Ralf Zichner, Thomas Blaudeck, Angela Thränhardt, Vincent Laude

Institutions: Centre National de la Recherche Scientifique, Chemnitz University of Technology, Université Marie et Louis Pasteur, Fraunhofer Institute for Electronic Nano Systems

Language: English

Topic: Acoustic Wave Phenomena Research

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Funder: Technische Universität Chemnitz

Award: G7963930855