Intrinsically low thermal conductivity of stoichiometric lithium niobate:Experimental measurement and microscopic origin
Abstract
With the rapid development of integrated electro-optic and nonlinear optical devices based on lithium niobate (LiNbO3, LN), thermal management is becoming a critical area of focus. However, experimental measurement of thermal transport in stoichiometric LiNbO3 (sLN) remains scarce, and the intrinsic microscopic mechanisms remain to be established. Here, we combine the laser pump-probe technique of frequency-domain thermoreflectance (FDTR) with state-of-the-art machine-learned atomistic simulations to comprehensively investigate thermal transport in sLN. The measured and simulated room-temperature thermal conductivity (κ) values of sLN agree well, which are orders-of-magnitude lower than that of many classic and emerging semiconductors such as silicon. Furthermore, the temperature-dependent κ exhibits a T−α scaling with α near unity, suggesting that thermal transport is dominated by intrinsic phonon-phonon scattering. By comparing sLN with cubic boron arsenide (cBAs) which serves as an ultrahigh-κ benchmark, we reveal that harmonic properties are not responsible for the low κ of sLN, which feature phonon heat capacity and group velocities that are either higher than or comparable to those in cBAs. Instead, the low κ originates from substantially stronger anharmonicity and larger scattering phase space. These two factors collectively suppress phonon lifetimes by 1-2 orders of magnitude, leading to a maximum phonon mean free path of approximately 140 nm. As a result, notable size effects emerge in thin-film sLN below 1 μm, with κ dropping to half the bulk value at 10 nm. Altogether, our findings establish a fundamental understanding of thermal transport in sLN and provide atomistic insights for thermal management in advanced lithium niobate technologies.
Versions
Related
- Streptavidin-Biotin Binding is Intrinsically Non-Cooperative, but Experimental Artefacts Can Induce Apparent Positive Cooperativity
- Universal scaling and measurability limits of thermal-conductivity measurement by a nanoscale point contact
- Experimental Measurement-Device-Independent Quantum Key distribution with Flawed State-Preparation over 300 km
- Experimental Measurement and Theoretical Analysis of Energy Relaxation Rates of an Interacting Two-Qubit System on a D-Wave Quantum Annealer
- Absolute Experimental Measurement of Intrinsic Helicity in Elementary Plasmonic Nanostructures
BibTeX
@misc{zhou2026intrinsically,
title = {{Intrinsically low thermal conductivity of stoichiometric lithium niobate:Experimental measurement and microscopic origin}},
author = {Wenjiang Zhou and Fuwei Yang and Yuxi Wang and Weiheng Li and Wujuan Yan and Kexin Zhang and Bai Song},
howpublished = {arXiv},
year = {2026},
month = jul,
doi = {10.48550/arxiv.2607.01673},
eprint = {2607.01673},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.01673},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Intrinsically low thermal conductivity of stoichiometric lithium niobate:Experimental measurement and microscopic origin
AU - Wenjiang Zhou
AU - Fuwei Yang
AU - Yuxi Wang
AU - Weiheng Li
AU - Wujuan Yan
AU - Kexin Zhang
AU - Bai Song
PY - 2026
DA - 2026/07/02
PB - arXiv
DO - 10.48550/arxiv.2607.01673
UR - https://arxiv.org/abs/2607.01673
AB - With the rapid development of integrated electro-optic and nonlinear optical devices based on lithium niobate (LiNbO_3, LN), thermal management is becoming a critical area of focus. However, experimental measurement of thermal transport in stoichiometric LiNbO_3 (sLN) remains scarce, and the intrinsic microscopic mechanisms remain to be established. Here, we combine the laser pump-probe technique of frequency-domain thermoreflectance (FDTR) with state-of-the-art machine-learned atomistic simulations to comprehensively investigate thermal transport in sLN. The measured and simulated room-temperature thermal conductivity (κ) values of sLN agree well, which are orders-of-magnitude lower than that of many classic and emerging semiconductors such as silicon. Furthermore, the temperature-dependent κ exhibits a T^−α scaling with α near unity, suggesting that thermal transport is dominated by intrinsic phonon-phonon scattering. By comparing sLN with cubic boron arsenide (cBAs) which serves as an ultrahigh-κ benchmark, we reveal that harmonic properties are not responsible for the low κ of sLN, which feature phonon heat capacity and group velocities that are either higher than or comparable to those in cBAs. Instead, the low κ originates from substantially stronger anharmonicity and larger scattering phase space. These two factors collectively suppress phonon lifetimes by 1-2 orders of magnitude, leading to a maximum phonon mean free path of approximately 140 nm. As a result, notable size effects emerge in thin-film sLN below 1 μm, with κ dropping to half the bulk value at 10 nm. Altogether, our findings establish a fundamental understanding of thermal transport in sLN and provide atomistic insights for thermal management in advanced lithium niobate technologies.
ER -