Thermal and electrostatic tuning of surface phonon-polaritons in LaAlO 3 /SrTiO 3 heterostructures.

Autor: Zhou Y; Department of Quantum Matter Physics, University of Geneva, CH-1211, Geneva, 4, Switzerland.; Beijing Key Laboratory of Nano-Photonics and Nano-Structure (NPNS), Department of Physics, Capital Normal University, 100048, Beijing, China., Waelchli A; Department of Quantum Matter Physics, University of Geneva, CH-1211, Geneva, 4, Switzerland., Boselli M; Department of Quantum Matter Physics, University of Geneva, CH-1211, Geneva, 4, Switzerland., Crassee I; Department of Quantum Matter Physics, University of Geneva, CH-1211, Geneva, 4, Switzerland., Bercher A; Department of Quantum Matter Physics, University of Geneva, CH-1211, Geneva, 4, Switzerland., Luo W; Department of Quantum Matter Physics, University of Geneva, CH-1211, Geneva, 4, Switzerland.; The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, School of Physics and TEDA Applied Physics Institute, Nankai University, Tianjin, 300457, China., Duan J; Department of Physics, University of Oviedo, Oviedo, 33006, Spain., van Mechelen JLM; Department of Electrical Engineering, Eindhoven University of Technology, 5600 MB, Eindhoven, Netherlands., van der Marel D; Department of Quantum Matter Physics, University of Geneva, CH-1211, Geneva, 4, Switzerland., Teyssier J; Department of Quantum Matter Physics, University of Geneva, CH-1211, Geneva, 4, Switzerland., Rischau CW; Department of Quantum Matter Physics, University of Geneva, CH-1211, Geneva, 4, Switzerland., Korosec L; Department of Quantum Matter Physics, University of Geneva, CH-1211, Geneva, 4, Switzerland., Gariglio S; Department of Quantum Matter Physics, University of Geneva, CH-1211, Geneva, 4, Switzerland., Triscone JM; Department of Quantum Matter Physics, University of Geneva, CH-1211, Geneva, 4, Switzerland., Kuzmenko AB; Department of Quantum Matter Physics, University of Geneva, CH-1211, Geneva, 4, Switzerland. Alexey.Kuzmenko@unige.ch.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2023 Nov 24; Vol. 14 (1), pp. 7686. Date of Electronic Publication: 2023 Nov 24.
DOI: 10.1038/s41467-023-43464-z
Abstrakt: Phonon polaritons are promising for infrared applications due to a strong light-matter coupling and subwavelength energy confinement they offer. Yet, the spectral narrowness of the phonon bands and difficulty to tune the phonon polariton properties hinder further progress in this field. SrTiO 3 - a prototype perovskite oxide - has recently attracted attention due to two prominent far-infrared phonon polaritons bands, albeit without any tuning reported so far. Here we show, using cryogenic infrared near-field microscopy, that long-propagating surface phonon polaritons are present both in bare SrTiO 3 and in LaAlO 3 /SrTiO 3 heterostructures hosting a two-dimensional electron gas. The presence of the two-dimensional electron gas increases dramatically the thermal variation of the upper limit of the surface phonon polariton band due to temperature dependent polaronic screening of the surface charge carriers. Furthermore, we demonstrate a tunability of the upper surface phonon polariton frequency in LaAlO 3 /SrTiO 3 via electrostatic gating. Our results suggest that oxide interfaces are a new platform bridging unconventional electronics and long-wavelength nanophotonics.
(© 2023. The Author(s).)
Databáze: MEDLINE
Externí odkaz: