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Title: Coupled Metamaterial–Phonon Terahertz Range Polaritons in a Topological Insulator
We report terahertz time-domain spectroscopy experiments demonstrating strong light–matter coupling in a terahertz LC metamaterial (MM) in which the phonon resonance of a topological insulator thin film is coupled to the photonic modes of an array of electronic split ring resonators. As we tune the MM resonance frequency through the frequency of the low-frequency α mode of (BixSb1–x)2Te3 (BST), we observe strong mixing and level repulsion between the phonon and MM resonance. This hybrid resonance is a phonon polariton. We observe a normalized coupling strength, η = ΩR/ωc ≈ 0.09, using the measured vacuum Rabi frequency and cavity resonance. Our results demonstrate that one can tune the mechanical properties of these materials by changing their electromagnetic environment and therefore modify their magnetic and topological degrees of freedom via coupling to the lattice in this fashion.  more » « less
Award ID(s):
2226666
PAR ID:
10515960
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
American Chemical Society
Date Published:
Journal Name:
ACS Photonics
Volume:
11
Issue:
6
ISSN:
2330-4022
Page Range / eLocation ID:
2242 to 2246
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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