Experimental Setup for Understanding the Superconductor to Insulator Transition in YBa

We refine a technique used by B. Boyce to change the carrier concentration level of thin YBa2Cu3O7-δ (YBCO) films. The purpose of this is to eventually study the superconductor to insulator transition that takes place in YBCO as carrier concentration level decreases. Introduction. For high carrier densities, YBCO is a d-wave superconductor, and its superfluid density has either a linear or a quadratic temperature dependence near zero temperature. However, for lower carrier densities (δ ~ 0.5 or lower), YBCO is an antiferromagnet. To understand how this material changes between these two states, a process to alter quickly the carrier concentration of YBCO is needed. This process must also yield a uniform carrier density throughout the crystal; else different regions of the film make transition at different average carrier concentration levels, resulting in a blur in the transition over several concentration levels. In YBCO crystals, there are both copper oxide chains and copper oxide planes. It is believed that conduction in YBCO takes place predominately within the copper oxide