Revealing Optically Induced Magnetization in SrTiO${}_3$ using Optically Coupled SQUID Magnetometry and Magnetic Circular Dichroism

Abstract

In this work, we study the time- and temperature-dependence of optically induced magnetization in bulk crystals of slightly oxygen-deficient SrTiO${}_{3-\delta }$ using an optically coupled SQUID magnetometer. We find that a weak ($\sim$5$\times$10${}^{-7}$~emu) but extremely long-lived (hours) magnetic moment can be induced in SrTiO${}_{3-\delta }$ at zero magnetic field by circular-polarized sub-bandgap light. We utilize this effect to demonstrate that SrTiO${}_{3-\delta }$ crystals can be used as an optically addressable magnetic memory by writing and subsequently reading magnetic patterns with light. The induced magnetization is consistent with that of a polarized ensemble of independent oxygen-vacancy-related complexes, rather than from collective or long-range magnetic order.

5 pages, 4 figures

References in corpus (4)

• Magnetic effects at the interface between nonmagnetic oxides
• Carrier-controlled ferromagnetism in SrTiO3
• Kerr effect as evidence of gyrotropic order in the cuprates
• Ab initio study of the two-dimensional metallic state at the surface of SrTiO3: importance of oxygen vacancies

Cited by in corpus (1)

• Controlling the magnetism of oxygen surface vacancies in strontium titanate $(\mathrm{SrTi}{\mathrm{O}}_3)$ through charging