Superconducting coplanar waveguide resonators for low temperature pulsed electron spin resonance spectroscopy

摘要

We discuss the design and implementation of thin film superconductingcoplanar waveguide micro- resonators for pulsed ESR experiments. Theperformance of the resonators with P doped Si epilayer samples is compared towaveguide resonators under equivalent conditions. The high achievable fillingfactor even for small sized samples and the relatively high Q-factor result ina sensitivity that is superior to that of conventional waveguide resonators, inparticular to spins close to the sample surface. The peak microwave power is onthe order of a few microwatts, which is compatible with measurements at ultralow temperatures. We also discuss the effect of the nonuniform microwavemagnetic field on the Hahn echo power dependence.