Persistent Optically Induced Magnetism in Oxygen-Deficient Strontium Titanate

Abstract

Strontium titanate (SrTiO${}_3$) is a foundational material in the emerging field of complex oxide electronics. While its electronic and optical properties have been studied for decades, SrTiO${}_3$ has recently become a renewed materials research focus catalyzed in part by the discovery of magnetism and superconductivity at interfaces between SrTiO${}_3$ and other oxides. The formation and distribution of oxygen vacancies may play an essential but as-yet-incompletely understood role in these effects. Moreover, recent signatures of magnetization in gated SrTiO${}_3$ have further galvanized interest in the emergent properties of this nominally nonmagnetic material. Here we observe an optically induced and persistent magnetization in oxygen-deficient SrTiO${}_{3-\delta }$ using magnetic circular dichroism (MCD) spectroscopy and SQUID magnetometry. This zero-field magnetization appears below ~18K, persists for hours below 10K, and is tunable via the polarization and wavelength of sub-bandgap (400-500nm) light. These effects occur only in oxygen-deficient samples, revealing the detailed interplay between magnetism, lattice defects, and light in an archetypal oxide material.

10 pages total

References in corpus (6)

• Magnetic effects at the interface between nonmagnetic oxides
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• Carrier-controlled ferromagnetism in SrTiO3
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Cited by in corpus (29)

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• Surface magnetism of strontium titanate
• Magnetism and metal-insulator transition in oxygen deficient SrTiO${}_3$
• Non-monotonic anisotropy in charge conduction induced by antiferrodistortive transition in metallic SrTiO${}_3$
• Electron dichotomy on the SrTiO${}_3$ defect surface augmented by many-body effects
• Mechanical dissipation from charge and spin transitions in oxygen deficient SrTiO_3
• Low Temperature Specific Heat of Doped SrTiO${}_3$: Doping Dependence of the Effective Mass and Kadowaki-Woods Scaling Violation
• Plentiful magnetic moments in oxygen deficient SrTiO3
• Local optical control of ferromagnetism and chemical potential in a topological insulator
• Spatially inhomogeneous electron state deep in the extreme quantum limit of strontium titanate
• Spin-texture induced by oxygen vacancies in Strontium perovskites (001) surfaces: A theoretical comparison between SrTiO3 and SrHfO3
• Controlling the magnetism of oxygen surface vacancies in strontium titanate $(\mathrm{SrTi}{\mathrm{O}}_3)$ through charging
• Interface exchange processes in LaAlO${}_3$/SrTiO${}_3$ induced by oxygen vacancies
• Manipulating Multiple Order Parameters via Oxygen Vacancies: The case of Eu0.5Ba0.5TiO3-δ
• Oxygen Vacancy-Induced Topological Hall effect in a Nonmagnetic Band Insulator
• Universality of Electron Mobility in LaAlO${}_3$/SrTiO${}_3$ and bulk SrTiO${}_3$
• Oxygen vacancy-induced anomalous Hall effect in a nominally non-magnetic oxide
• Dislocation Majorana zero modes in perovskite oxide 2DEG
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• Polaronic nature of a muonium-related paramagnetic center in SrTiO${}_3$
• Structure and ferromagnetic instability of the oxygen-deficient SrTiO${}_3$ surface
• Negatively Charged Muonium and Related Centers in Solids
• Photo-enhanced magnetization in Fe-doped ZnO nanowires
• Dynamic defect correlations dominate activated electronic transport in SrTiO3
• Revealing Optically Induced Magnetization in SrTiO${}_3$ using Optically Coupled SQUID Magnetometry and Magnetic Circular Dichroism
• Chargeable photoconductivity in Van der Waals heterojunctions