Structural and subband changes at the LaAlO3/SrTiO3 interface investigated by two-dimensional correlation spectroscopy

The interplay among many ground states in correlated electron materials, especially at the LaAlO3/SrTiO3 interface is central in deeply understanding the physical characteristics and improving further applications of these materials. Here, we use two-dimensional infrared correlation spectroscopy to study the influence of magnetic fields and temperature on the mid-infrared spectral responsivity of the interface. The magnetic field plays the main role at temperatures below the transition temperature, TC. Two additional spectral peaks were identified at wavelengths of 2800 nm and 3400 nm, when compared with our prior studies. All of these response bands are related to the spin-orbit coupling effect and crystal structure changes. Detailed structural and subband changes in the interface are also investigated.