IQST Grad School Project

Layer selective reduction of rare earth nickelate superlattices

Project Description:

Nowadays the synthesis of nanostructured materials with specialized quantum properties, like superconductivity, is possible. In particular, the past years have seen tremendous progress in the growth of nanoscale complex oxide heterostructures with atomically sharp interfaces and a quality comparable to semiconductor-based multilayers [3]. Complex oxides offer a much larger variety of available quantum states and possibilities of their manipulation through external parameters, like electric or magnetic fields, temperature, light, structural distortions, and pressure [4]. In a thin film or multilayer further degrees of freedom, like epitaxial strain, charge transfer and electronic confinement, allow novel quantum effects to emerge, including even superconductivity [5]. A more selective approach to search for new superconductors is to combine oxide materials with individual properties that are believed to be important for the occurrence of high-Tc superconductivity together in a heterostructure. Model calculations have shown that superlattices composed of rare-earth nickel oxide and a band-gap insulator may host physics similar to that of the high-Tc cuprates [6,7]. This theoretical work has recently initiated a lot of research activity, but experimental evidence for superconductivity has not been reported so far. We would like to take this initial idea a step further and create a material with quantum states which cannot be obtained under equilibrium conditions.