Semiclassical theory of anisotropic transport at LaAlO3/SrTiO3 interfaces under in-plane magnetic field

Abstract

The unconventional magnetotransport at the interface between transition-metal oxides $LaAl{O}_3$ (LAO) and $SrTi{O}_3$ (STO) is frequently related to mobile electrons interacting with localized magnetic moments. However nature and properties of magnetism at this interface are not well understood so far. In this paper, we focus on transport effects driven by spin-orbit coupling and intentionally neglect possible strong correlations. The electrical resistivity tensor is calculated as a function of the magnitude and orientation of an external magnetic field parallel to the interface. The semiclassical Boltzmann equation is solved numerically for the two-dimensional system of spin-orbit coupled electrons accelerated by an electric field and scattered by spatially-correlated impurities. At temperatures of a few Kelvin and densities such that the chemical potential crosses the second pair of spin-orbit split bands, we find a strongly anisotropic modulation of the (negative) magnetoresistance above 10 T, characterized by multiple maxima and minima away from the crystalline axes. Along with the drop of the magnetoresistance, an abrupt enhancement of the transverse resistivity occurs. The angular modulation of the latter considerably deviates from a (low-field) sinusoidal dependence to a (high-field) step-like behaviour. These peculiar features are the consequences of the anisotropy of both (intra-band and inter-band ) scattering-amplitudes in the Brillouin zone when the relevant energy scales in the system - chemical potential, spin-orbit interaction and Zeeman energy - are all comparable to each other. The theory provides good qualitative agreement with experimental data in the literature.

14 pages, 9 figures, 2 appendices. Extended version with discussion section widely revised, additional results for different parameters in Appendix B, theoretical model presented in details in Appendix A. To be published in Phys. Rev. B

References in corpus (15)

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• Observation of Inverse Edelstein Effect in Rashba-Split 2DEG between SrTiO3 and LaAlO3 at Room Temperature
• Rashba induced magnetoconductance oscillations in the LaAlO3-SrTiO3 heterostructure
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• Quantum-Matter Heterostructures
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• Nature of Orbital and Spin Rashba Coupling in the Surface Bands of SrTiO3 and KTaO3
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• Nernst effect beyond the relaxation-time approximation
• Surface roughness scattering in multisubband accumulation layers
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Cited by in corpus (8)

• Anisotropic magnetoresistance: materials, models and applications
• Six-fold crystalline anisotropic magnetoresistance in the (111) LaAlO${}_3$/SrTiO${}_3$ oxide interface
• From low-field Sondheimer oscillations to high-field very large and linear magnetoresistance in a SrTiO${}_3$-based two-dimensional electron gas
• The mechanism of spin-orbit coupling in a 2D oxide interface
• Van Hove scenario of anisotropic transport in a two-dimensional spin-orbit coupled electron gas in an in-plane magnetic field
• Anisotropic Magnetoresistance in Multiband Systems: 2DEGs and Polar Metals at Oxide Interfaces
• Inhomogeneous superconductivity and quasilinear magnetoresistance at amorphous LaTiO3/SrTiO3 interfaces
• Fluctuations superconductivity and giant negative magnetoresistance in a gate voltage tuned 2D electron liquid with strong spin-orbit impurity scattering