Disentangling the dynamics of transient spin and orbital magnetization in SrTiO$_3$ via the inverse Faraday effect from RT-TDDFT
Fuente:
arXiv
Guardado en:
| Autores principales: | , , |
|---|---|
| Formato: | Preprint |
| Publicado: |
2026
|
| Materias: | |
| Acceso en línea: | |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| _version_ | 1866912923093303296 |
|---|---|
| author | Darmawan, Andri Gruner, Markus E. Pentcheva, Rossitza |
| author_facet | Darmawan, Andri Gruner, Markus E. Pentcheva, Rossitza |
| contents | Light-matter interaction allows to achieve non-equilibrium states that are otherwise inaccessible. Motivated by recent experiments that report ferroelectricity -- and even multiferroicity -- in the prototypical diamagnetic band insulator SrTiO$_3$ induced by terahertz pulses, we investigate the carrier and magnetization dynamics of SrTiO$_3$ excited optically by linearly and circularly polarized light. Our real-time time-dependent density-functional theory (RT-TDDFT) results reveal a highly non-trivial, site- and orbital-dependent temporal evolution with charge transferred from O $2p$ to Ti $3d$ states. For linearly polarized light the orbitally polarized lobes of electron density at the oxygen and titanium sites fluctuate out-of-phase, resembling the soft transverse optical phonon mode, dynamically breaking inversion symmetry. In contrast, circularly polarized pulses induce a coherent rotation of the charge dipoles around O. This induces a helicity-dependent finite transient magnetization with opposite sign for oxygen and Ti even without ionic motion. Detailed analysis reveals that the dominant mechanism is the transfer of angular momentum of light to the electronic orbital angular momentum, while spin-orbit coupling plays a key role in the transfer from orbital to spin angular momentum, the former being an order of magnitude larger than the latter. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2602_20693 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Disentangling the dynamics of transient spin and orbital magnetization in SrTiO$_3$ via the inverse Faraday effect from RT-TDDFT Darmawan, Andri Gruner, Markus E. Pentcheva, Rossitza Materials Science Light-matter interaction allows to achieve non-equilibrium states that are otherwise inaccessible. Motivated by recent experiments that report ferroelectricity -- and even multiferroicity -- in the prototypical diamagnetic band insulator SrTiO$_3$ induced by terahertz pulses, we investigate the carrier and magnetization dynamics of SrTiO$_3$ excited optically by linearly and circularly polarized light. Our real-time time-dependent density-functional theory (RT-TDDFT) results reveal a highly non-trivial, site- and orbital-dependent temporal evolution with charge transferred from O $2p$ to Ti $3d$ states. For linearly polarized light the orbitally polarized lobes of electron density at the oxygen and titanium sites fluctuate out-of-phase, resembling the soft transverse optical phonon mode, dynamically breaking inversion symmetry. In contrast, circularly polarized pulses induce a coherent rotation of the charge dipoles around O. This induces a helicity-dependent finite transient magnetization with opposite sign for oxygen and Ti even without ionic motion. Detailed analysis reveals that the dominant mechanism is the transfer of angular momentum of light to the electronic orbital angular momentum, while spin-orbit coupling plays a key role in the transfer from orbital to spin angular momentum, the former being an order of magnitude larger than the latter. |
| title | Disentangling the dynamics of transient spin and orbital magnetization in SrTiO$_3$ via the inverse Faraday effect from RT-TDDFT |
| topic | Materials Science |
| url | https://arxiv.org/abs/2602.20693 |