The innovation engine for new materials

Lisa Sirén Gustafsson

Lisa Sirén Gustafsson

University: 

Chalmers University of Technology

Major: 

Materials Chemistry

Mentor(s): 

Xiang Chen

Faculty Sponsor(s): 

Stephen Wilson

Faculty Sponsor's Department: 

Materials

Project Title: 

Ionic gating of the electronic properties in Sr2IrO4

Project Description: 

Since its discovery in 1911, superconductivity has been of significant interest due to its fascinating properties and broad potential applications. Most known superconducting materials are only superconducting at low temperatures (below 30K), which is why it is of importance to find new high temperature superconductors for practical applications. Despite tremendous efforts to search for possible room temperature superconductors the record holders are limited to the Cu-based families (without applying pressure) and the nature of their underlying superconducting mechanism are still not fully understood. Recently interest in realizing the potential superconductivity in the 5d Mott insulator Sr2IrO4 has arisen due to the similarities in crystal structure, electronic structure and magnetic coupling constants compared to the superconducting parent compound La2CuO4. Signatures of superconducting states have been reported in surface doped Sr2IrO4, but bulk superconducting states have still not been realized regardless of remarkable experimental efforts, including chemical doping. One potential solution for realizing superconductivity within Sr2IrO4 would be electric field controlled tuning of charge carrier density. Here we strive for tuning the charge carrier density of Sr2IrO4 by gating after laminating a thin film of ion gel on top of a clean and newly revealed fresh surface of the bulk single crystal. The usage of ion gel would potentially overcome the intrinsic limits of the amount of the carrier density tuned by chemical doping in bulk crystals by attaining a higher carrier density. The electronic and entangled magnetic properties of Sr2IrO4 are explored through this relative new technique, and it could lead to future possible applications utilizing strong spin-orbit coupling in 5d compounds.