Comparison of coherent phonon generation by electronic and ionic Raman scattering in LaAlO3
OPEN ACCESS
Loading...
Author / Producer
Date
2021-02
Publication Type
Journal Article
ETH Bibliography
yes
Citations
Altmetric
OPEN ACCESS
Data
Rights / License
Abstract
In ionic Raman scattering, infrared-active phonons mediate a scattering process that results in the creation or destruction of a Raman-active phonon. This mechanism relies on nonlinear interactions between phonons and has in recent years been associated with a variety of emergent lattice-driven phenomena in complex transition-metal oxides, but the underlying mechanism is often obscured by the presence of multiple coupled order parameters in play. Here, we use time-resolved spectroscopy to compare coherent phonons generated by ionic Raman scattering with those created by more conventional electronic Raman scattering on the nonmagnetic and non-strongly-correlated wide-band-gap insulator LaAlO3. We find that the oscillatory amplitude of the low-frequency Raman-active Eg mode exhibits a sharp peak when we tune our pump frequency into resonance with the high-frequency infrared-active Eu mode, consistent with first-principles calculations. Our results suggest that ionic Raman scattering can strongly dominate electronic Raman scattering in wide-band-gap insulating materials. We also see evidence of competing scattering channels at fluences above 28mJ/cm2 that alter the measured amplitude of the coherent phonon response.
Permanent link
Publication status
published
Editor
Book title
Journal / series
Volume
3 (1)
Pages / Article No.
13126
Publisher
American Physical Society
Event
Edition / version
Methods
Software
Geographic location
Date collected
Date created
Subject
Anharmonic lattice dynamics; Electron-phonon coupling; Optical phonons; perovskite; wide band gap systems; Femtosecond laser spectroscopy; Time-resolved light scattering spectroscopy
Organisational unit
03903 - Spaldin, Nicola A. / Spaldin, Nicola A.
03920 - Johnson, Steven / Johnson, Steven
Notes
Funding
169698 - Nonlinear phononic control over transition metal perovskites and interfaces (SNF)
291151 - Coupled and Competing Instabilities in Complex Oxides (EC)
291151 - Coupled and Competing Instabilities in Complex Oxides (EC)
Related publications and datasets
Is supplemented by: