Guang-Lin Zhao
Southern University and A&M College, USA
Title: The puzzle of anomalous isotope effect in high and low Tc superconductors
Biography
Biography: Guang-Lin Zhao
Abstract
Superconductors have zero electrical resistance and expulsion of magnetic fields below a critical temperature Tc. They can carry electric current without any energy loss and have many applications. However, understanding superconductivity is a great challenge. Especially, anomalously small isotope effect in some high Tc superconductors such as YBa2Cu3O7 (YBCO) created a great challenge for understanding. To solve the puzzle, a new methodology is implemented by integrating first-principles calculations of electronic structures of the materials into the theory of many-body physics for superconductivity. The aim is to seek a unified methodology to study the electronic and superconducting properties of the materials. It is demonstrated from first-principles that the extended saddle point singularities in the electronic structure of some high and low Tc superconductors such as YBCO, Nb3Sn, Zr, strongly correlate with the anomalous isotope effect in these superconductors. Some guidance for finding new high Tc superconductors will also be discussed.