Twist-tunable in-plane anisotropic polaritonic crystals

Capote-Robayna, Nathaniel ; Tresguerres-Mata, Ana I. F. ; Tarazaga Martín-Luengo, Aitana ; Terán-García, Enrique ; Martin-Moreno, Luis ; Alonso-González, Pablo ; Nikitin, Alexey Y.

Resumen: van der Waals (vdW) materials supporting phonon polaritons (PhPs) – light coupled to lattice vibrations – have gathered significant interest because of their intrinsic anisotropy and low losses. In particular, α-MoO3 supports PhPs with in-plane anisotropic propagation, which has been exploited to tune the optical response of twisted bilayers and trilayers. Additionally, various studies have explored the realization of polaritonic crystals (PCs) – lattices with periods comparable to the polariton wavelength. PCs consisting of hole arrays etched in α-MoO3 slabs exhibit Bragg resonances dependent on the angle between the crystallographic axes and the lattice vectors. However, such PC concept, with a fixed orientation and size of its geometrical parameters, constrains practical applications and introduces additional scattering losses due to invasive fabrication processes. Here, we demonstrate a novel PC concept that overcomes these limitations, enabling low-loss optical tuning. It comprises a rotatable pristine α-MoO3 layer located on a periodic hole array fabricated in a metallic layer. Our design prevents degradation of the α-MoO3 optical properties caused by fabrication, preserving its intrinsic low-loss and in-plane anisotropic propagation of PhPs. The resulting PC exhibits rotation of the Bloch modes, which is experimentally visualized by scanning near-field microscopy. In addition, we experimentally determine the polaritons momentum and reconstruct their band structure. These results pave the way for mechanically tunable nano-optical components based on polaritons for potential lasing, sensing, or energy harvesting applications.

Idioma: Inglés

DOI: 10.1515/nanoph-2024-0462

Año: 2024

Publicado en: Nanophotonics 13, 26 (2024), 4761-4770
ISSN: 2192-8606

Factor impacto JCR: 6.6 (2024)

Categ. JCR: MATERIALS SCIENCE, MULTIDISCIPLINARY rank: 112 / 460 = 0.243 (2024) - Q1 - T1
Categ. JCR: OPTICS rank: 19 / 125 = 0.152 (2024) - Q1 - T1
Categ. JCR: PHYSICS, APPLIED rank: 35 / 187 = 0.187 (2024) - Q1 - T1
Categ. JCR: NANOSCIENCE & NANOTECHNOLOGY rank: 41 / 147 = 0.279 (2024) - Q2 - T1

Factor impacto SCIMAGO: 1.765 - Atomic and Molecular Physics, and Optics (Q1) - Biotechnology (Q1) - Electronic, Optical and Magnetic Materials (Q1) - Electrical and Electronic Engineering (Q1)

Financiación: info:eu-repo/grantAgreement/ES/AEI/PID2022-141304NB-100
Financiación: info:eu-repo/grantAgreement/ES/AEI/PID2023-147676NB-100
Financiación: info:eu-repo/grantAgreement/ES/DGA/Q-MAD
Financiación: info:eu-repo/grantAgreement/ES/MICINN AEI PID2019-111156GB-I00
Financiación: info:eu-repo/grantAgreement/ES/MICINN-AEI/PID2020-115221GB-C41

Tipo y forma: Article (Published version)