Strain-induced Dynamic Spin-Phonon Coupling in Epitaxial RuO2 Films
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866915520179077120 |
|---|---|
| author | Choi, In Hyeok Jeong2, Seung Gyo Lee, Jae Hyuck Kang, San Nair, Sreejith Kim, Changyoung Wulferding, Dirk Jalan, Bharat Lee, Jong Seok |
| author_facet | Choi, In Hyeok Jeong2, Seung Gyo Lee, Jae Hyuck Kang, San Nair, Sreejith Kim, Changyoung Wulferding, Dirk Jalan, Bharat Lee, Jong Seok |
| contents | Magnetic order parameters in altermagnets can couple to quantized lattice vibration via both piezomagnetic and magnetoelastic effects, leading to the renormalization of phonon dispersion. Here, we demonstrate photo-induced dynamic frequency modulation of THz phonons excited in anisotropically-strained epitaxial RuO2 thin films using ultrafast coherent phonon spectroscopy and time-resolved magneto-optic Kerr effect measurement. A coherent oscillation of a transverse acoustic phonon appears in the sub-THz range with increasing film thickness above 4 nm due to local dislocation arising from the anisotropic strain relaxation, which hosts large non-zero shear strain. Interestingly, this phonon mode exhibits a time-varying mode hardening below ~ 500 K. Furthermore, an optical phonon oscillation emerges in magnetization dynamics of the photo-induced non-equilibrium state, and it becomes significantly softened near the critical temperature, while there is no observable magneto-optic signal in fully-strain-relaxed films. Such notable dynamic frequency modulations in acoustic and optical phonons offer an opportunity to manipulate phonons in the THz range through the spin-phonon coupling controlled by epitaxial design, which can inspire the new class of altermagnetic applications in the ultrafast quantum opto-spintronics. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2509_23969 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Strain-induced Dynamic Spin-Phonon Coupling in Epitaxial RuO2 Films Choi, In Hyeok Jeong2, Seung Gyo Lee, Jae Hyuck Kang, San Nair, Sreejith Kim, Changyoung Wulferding, Dirk Jalan, Bharat Lee, Jong Seok Materials Science Other Condensed Matter Magnetic order parameters in altermagnets can couple to quantized lattice vibration via both piezomagnetic and magnetoelastic effects, leading to the renormalization of phonon dispersion. Here, we demonstrate photo-induced dynamic frequency modulation of THz phonons excited in anisotropically-strained epitaxial RuO2 thin films using ultrafast coherent phonon spectroscopy and time-resolved magneto-optic Kerr effect measurement. A coherent oscillation of a transverse acoustic phonon appears in the sub-THz range with increasing film thickness above 4 nm due to local dislocation arising from the anisotropic strain relaxation, which hosts large non-zero shear strain. Interestingly, this phonon mode exhibits a time-varying mode hardening below ~ 500 K. Furthermore, an optical phonon oscillation emerges in magnetization dynamics of the photo-induced non-equilibrium state, and it becomes significantly softened near the critical temperature, while there is no observable magneto-optic signal in fully-strain-relaxed films. Such notable dynamic frequency modulations in acoustic and optical phonons offer an opportunity to manipulate phonons in the THz range through the spin-phonon coupling controlled by epitaxial design, which can inspire the new class of altermagnetic applications in the ultrafast quantum opto-spintronics. |
| title | Strain-induced Dynamic Spin-Phonon Coupling in Epitaxial RuO2 Films |
| topic | Materials Science Other Condensed Matter |
| url | https://arxiv.org/abs/2509.23969 |