Magnetic field resilient lumped element superconducting resonators

Abstract

Resonators are useful structures due to their simplicity in modeling, design, fabrication and measurement. They can be measured over a wide range of frequencies, power and temperatures, making them convenient for many experiments. Recently, superconducting resonators started being used to investigate microscopic phenomena which require applied magnetic fields of the order of 1T, such as Majorana physics. For this kind of applications it is important that resonators maintain high quality factors in the presence of magnetic fields. A suitable candidate easy to fabricate, resilient to applied fields, and simple capacitive coupling is the lumped element resonator. Such a type of resonator has already been used for some experiments that require magnetic fields, but a systematic study on the resonator’s optimal geometry is yet to be undertaken. The aim of this thesis is to investigate the role of lumped element resonator geometry in its quality factor. That is how to optimize the resonator’s design for enhanced performance of the resonator even in the presence of applied magnetic fields.