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Iglesias Martínez JA, Groß MF, Chen Y, Frenzel T, Laude V, Kadic M, Wegener M. Experimental observation of roton-like dispersion relations in metamaterials. SCIENCE ADVANCES 2021; 7:eabm2189. [PMID: 34851658 PMCID: PMC8635434 DOI: 10.1126/sciadv.abm2189] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 10/13/2021] [Indexed: 05/21/2023]
Abstract
Previously, rotons were observed in correlated quantum systems at low temperatures, including superfluid helium and Bose-Einstein condensates. Here, following a recent theoretical proposal, we report the direct experimental observation of roton-like dispersion relations in two different three-dimensional metamaterials under ambient conditions. One experiment uses transverse elastic waves in microscale metamaterials at ultrasound frequencies. The other experiment uses longitudinal air-pressure waves in macroscopic channel–based metamaterials at audible frequencies. In both experiments, we identify the roton-like minimum in the dispersion relation that is associated to a triplet of waves at a given frequency. Our work shows that designed interactions in metamaterials beyond the nearest neighbors open unprecedented experimental opportunities to tailor the lowest dispersion branch—while most previous metamaterial studies have concentrated on shaping higher dispersion branches.
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Affiliation(s)
| | - Michael Fidelis Groß
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe 76128, Germany
| | - Yi Chen
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe 76128, Germany
- Corresponding author. (Y.C.); (M.W.)
| | - Tobias Frenzel
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe 76128, Germany
| | - Vincent Laude
- Institut FEMTO-ST, UMR 6174, CNRS, Université de Bourgogne Franche-Comté, Besançon, 25030, France
| | - Muamer Kadic
- Institut FEMTO-ST, UMR 6174, CNRS, Université de Bourgogne Franche-Comté, Besançon, 25030, France
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Karlsruhe 76128, Germany
| | - Martin Wegener
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe 76128, Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Karlsruhe 76128, Germany
- Corresponding author. (Y.C.); (M.W.)
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Köpfler J, Frenzel T, Schmalian J, Wegener M. Fused-Silica 3D Chiral Metamaterials via Helium-Assisted Microcasting Supporting Topologically Protected Twist Edge Resonances with High Mechanical Quality Factors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2103205. [PMID: 34398466 DOI: 10.1002/adma.202103205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/24/2021] [Indexed: 06/13/2023]
Abstract
It is predicted theoretically that a 1D diatomic chain of 3D chiral cells can support a topological bandgap that allows for translating a small time-harmonic axial movement at one end of the chain into a resonantly enhanced large rotation of an edge state at the other end. This edge state is topologically protected such that an arbitrary mass of a mirror at the other end does not shift the eigenfrequency out of the bandgap. Herein, this complex 3D laser-beam-scanner microstructure is realized in fused-silica form. A novel microcasting approach is introduced that starts from a hollow polymer cast made by standard 3D laser nanoprinting. The cast is evacuated and filled with helium, such that a highly viscous commercial glass slurry is sucked in. After UV curing and thermal debinding of the polymer, the fused-silica glass is sintered at 1225 °C under vacuum. Detailed optical measurements reveal a mechanical quality factor of the twist-edge resonance of 2850 at around 278 kHz resonance frequency under ambient conditions. The microcasting approach can likely be translated to many other glasses, to metals and ceramics, and to complex architectures that are not or not yet amenable to direct 3D laser printing.
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Affiliation(s)
- Julian Köpfler
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76128, Karlsruhe, Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76021, Karlsruhe, Germany
| | - Tobias Frenzel
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76128, Karlsruhe, Germany
| | - Jörg Schmalian
- Institute for Theoretical Condensed Matter Physics, Karlsruhe Institute of Technology (KIT), 76128, Karlsruhe, Germany
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology (KIT), 76021, Karlsruhe, Germany
| | - Martin Wegener
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76128, Karlsruhe, Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76021, Karlsruhe, Germany
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