Quantum oscillations and subband properties of the two-dimensional electron gas at the LaAlO3/SrTiO3 interface

TL;DR

This study uses high magnetic field measurements to explore the properties of the two-dimensional electron gas at LaAlO3/SrTiO3 interfaces, revealing multiple subbands, their effective masses, and scattering behaviors.

Contribution

It provides detailed characterization of subband structure, effective masses, and scattering mechanisms in the 2D electron gas at the heterostructure interface.

Findings

Multiple 2D conduction subbands identified

Effective masses between 1 and 3 times electron mass

Quantum mobilities around 3000 cm^2/V s

Abstract

We have performed high field magnetotransport measurements to investigate the interface electron gas in LaAlO3/SrTiO3 heterostructures. Shubnikov-de Haas oscillations reveal several 2D conduction subbands with carrier effective masses between 1 and 3 m_e, quantum mobilities of order 3000 cm^2/V s, and band edges only a few millielectronvolts below the Fermi energy. Measurements in tilted magnetic fields confirm the 2D character of the electron gas, and show evidence of inter-subband scattering.