Coupling Among Carriers and Phonons in Femtosecond Laser Pulses Excited SrRuO₃: A Promising Candidate for Optomechanical and Optoelectronic Applications

Abstract

Large reversible lattice strain that manipulates coupled degrees of freedom can be induced by optics in SrRuO 3 , suggesting it has great potential in optomechanical and optoelectronic devices. Photoexcitation and energy transfer via electron−phonon scattering have been studied, but recent studies inferred that more processes that remain to be identified contribute to the light-induced deformation. Here, by combining ultrafast X-ray diffraction and ultrafast optical reflectivity experiments, we image the excitation and relaxation characteristics of SrRuO 3 films. Upon photoexcitation, photocarriers redistribute both in space and energy and then relax with fast direct recombination, phonon-assisted relaxation and phonon−phonon scattering dominating on a longer time scale. The phonon-assisted relaxation process, together with the thermal effect resulting from the electron−phonon scattering on sub-picosecond time scales, contributes to the photoinduced strain in SrRuO 3 . Phonon and electron effects on relaxations of SrRuO 3 are studied, including the bottleneck effects of phonons on the coupled carrier and phonon relaxation and the scaled relationship of the fast carrier relaxation with the electron correlation. Our results suggest optomechanical and optoelectronic manipulations of SrRuO 3 by electronic pumping, providing avenues for designs of applications with high performance.

Extended Oxygen Octahedral Tilt Proximity near Oxide Heterostructures

“…Note that the g coefficient is proportional to the dispersion of relevant phonon modes. , In correlated metallic systems such as SRO, phonon dispersion can be further renormalized by electron–phonon coupling . According to previous angle-resolved photoemission (ARPES) studies, − a kink dispersion in the d xz /yz band of SRO can originate from electron–phonon coupling, particularly with oxygen-related phonons . To investigate the electron–phonon coupling of SRO, we measured dispersions of the d xz /yz band in 15 uc of SRO films with −0.5 and +1.5% strains by in situ ARPES (Figure S16, Supporting Information).…”

Giant Enhancement of Electron–Phonon Coupling in Dimensionality‐Controlled SrRuO3 Heterostructures

“…Above a single‐film thickness of 20 uc, G ep is estimated to be as low as 10 15 W m −3 K −1 similar to bulk SRO. [ 32 ] As x decreases, G ep increases significantly to about 10 17 W m −3 K −1 for 3 uc of SRO single‐films. More interestingly, G ep of the SRO/STO SLs is further enhanced by an order of magnitude greater than that of a single‐film at the same x .…”

A Two-Step Femtosecond Laser-Based Deposition of Robust Corrosion-Resistant Molybdenum Oxide Coating

“…Materials processing using femtosecond lasers was first demonstrated in 1987 by Küper and Stuke [10], and Srinivasan et al [11]. At present, femtosecond lasers are used for micro and nanoprocessing of materials for optics [12], electronics [13], optoelectronics [14], photonics [15], photovoltaics [16], photolithography [17], microchanneling [18], optofluidics [19], optomechanics [20], additive manufacturing [21], surface micro-and nanostructuring [22], glass welding [23], corrosion inhibition [24], and tissue engineering [25].…”