Optically tuned dimensionality crossover in photocarrier-doped SrTiO${}_3$: onset of weak localization

Abstract

We report magnetotransport properties of photogenerated electrons in undoped SrTiO${}_3$ single crystals under ultraviolet illumination down to 2 K. By tuning the light intensity, the steady state carrier density can be controlled, while tuning the wavelength controls the effective electronic thickness by modulating the optical penetration depth. At short wavelengths, when the sheet conductance is close to the two-dimensional Mott minimum conductivity we have observed critical behavior characteristic of weak localization. Negative magnetoresistance at low magnetic field is highly anisotropic, indicating quasi-two-dimensional electronic transport. The high mobility of photogenerated electrons in SrTiO${}_3$ allows continuous tuning of the effective electronic dimensionality by photoexcitation.

7 pages, 7 figures

References in corpus (5)

• Metallic behavior and related phenomena in two dimensions
• Universality of the Mott-Ioffe-Regel limit in metals
• Lattice relaxation, electronic screening, and spin and orbital phase diagram of LaTiO${}_3$/SrTiO${}_3$ superlattices
• Lattice polarization effects on electron-gas charge densities in ionic superlattices
• Low temperature metallic state induced by electrostatic carrier doping of SrTiO${}_3$

Cited by in corpus (10)

• Creation and control of a two-dimensional electron liquid at the bare SrTiO3 surface
• Dynamical response and confinement of the electrons at the LaAlO3/SrTiO3 interface
• Enhanced persistent photoconductivity in $\delta$-doped LaAlO${}_3$/SrTiO${}_3$ heterostructures
• Optically excited multi-band conduction in LaAlO3/SrTiO3 heterostructures
• Vanishing Hall Coefficient in the Extreme Quantum Limit in Photocarrier-Doped SrTiO3
• Enhanced spin-orbit coupling and charge carrier density suppression in LaAl1-xCrxO3/SrTiO3 heterointerfaces
• Infrared ellipsometry study of the confined electrons in a high-mobility $\gamma$-Al${}_2$O${}_3$/SrTiO${}_3$ heterostructure
• Infrared ellipsometry study of the photo-generated charge carriers at the (001) and (110) surfaces of SrTiO${}_3$ crystals and the interface of corresponding LaAlO${}_3$/SrTiO${}_3$ heterostructures
• Gate voltage control of the $Al{O}_x$/$SrTi{O}_3$ interface electrical properties
• Anisotropy of the infrared-active phonon modes in the mono-domain state of tetragonal SrTiO3 (110)