BYU

Abstract by Alden Pack

Personal Infomation


Presenter's Name

Alden Pack

Degree Level

Doctorate

Abstract Infomation


Department

Physics and Astronomy

Faculty Advisor

Mark Transtrum

Title

Analyzing the Metastability of Superconductors Using Automatic Differentiation

Abstract

A defining characteristic of superconductivity is the Meissner effect, i.e., expulsion of applied magnetic fields. For large fields, the Meissner effect breaks down and the superconductor transitions to a normal metal. The theoretical upper limit is known as the "superheating field", above which magnetic vortices spontaneously enter the superconductor. Particle accelerators use alternating electric fields in superconducting resonance cavities to accelerate charged particles. The absolute limit to cavity performance occurs when the induced magnetic field reaches the superheating field. I calculate both the superheating field and the vortex spacing using a linear stability analysis. I use automatic differentiation to calculate derivatives of complex free energy functionals. This approach will enable material specific predictions using sophisticated models of superconductivity.