Broad spectral tuning of ultra-low-loss polaritons in a van der Waals crystal by intercalation.
Nat Mater
; 19(9): 964-968, 2020 Sep.
Article
in En
| MEDLINE
| ID: mdl-32284598
ABSTRACT
Phonon polaritons-light coupled to lattice vibrations-in polar van der Waals crystals are promising candidates for controlling the flow of energy on the nanoscale due to their strong field confinement, anisotropic propagation and ultra-long lifetime in the picosecond range1-5. However, the lack of tunability of their narrow and material-specific spectral range-the Reststrahlen band-severely limits their technological implementation. Here, we demonstrate that intercalation of Na atoms in the van der Waals semiconductor α-V2O5 enables a broad spectral shift of Reststrahlen bands, and that the phonon polaritons excited show ultra-low losses (lifetime of 4 ± 1 ps), similar to phonon polaritons in a non-intercalated crystal (lifetime of 6 ± 1 ps). We expect our intercalation method to be applicable to other van der Waals crystals, opening the door for the use of phonon polaritons in broad spectral bands in the mid-infrared domain.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Nat Mater
Journal subject:
CIENCIA
/
QUIMICA
Year:
2020
Document type:
Article
Affiliation country:
Spain