This interdisciplinary project incorporates the disciplines of Physics, Chemistry and Engineering . However the project is specifically housed within the Hope College Department of Physics.
(1) We are investigating ways to manipulate the nonlinearity characteristic of superconducting thin films. A microwave sapphire resonator is used to measure the surface resistance of superconducting thin films, and high-temperature annealing protocols are employed to alter the auto-doping level of the films. The altered doping in the films causes the nonlinear surface impedance to shift to a new regime on the nonlinearity characteristic curve.
(2) Some of the films have been patterned into devices and your research will examine their device properties. In your research you can probe the electrical nonlinearity near the superconducting phase transition, compare the nonlinearities of different superconducting materials, and investigate the effects of device fabrication on nonlinearity. We are developing a micromanipulated probe station to locally probe the generation of nonlinear distortion in a superconducting device.
You will learn the tools of the trade in high frequency engineering including microwave test and measurement, electromagnetic design and analysis (EDA), and microwave device packaging.
This research will include some classroom instruction on the research topic along with required group meetings. Hope students are expected to start working before the summer, and to continue into next year. Non-Hope applicants are welcome to apply! A 42 hour training course (PHYS 495, Microwave Engineering and Device Physics) will be given during the week prior to the start date and all accepted applicants are strongly encouraged to participate. Contact Prof. Remillard for details. Gen Phys II Lab, PHYS 142, is a must. A higher proficiency in E&M (PHYS 342) is highly recommended.
Bradley J. Dober and S.K. Remillard, Harmonic and Intermodulation Distortion in a Superconducting Microwave Resonator, American Physical Society, March Meeting, March 17, (2009).
Evan K. Pease, Bradley J. Dober, and S.K. Remillard, Synchronous measurement of even and odd order intermodulation distortion at the resonant frequency of a superconducting resonator, Reviews of Scientific Instruments vol. 81, 024701 (2010).
Evan K. Pease and S.K. Remillard, "Time-Reversal Symmetry Breaking in the Non-Linear Distortion from Superconducting Circuits", American Physical Society, March Meeting, March, (2010).
Annelle M. Eben, V. Andrew Bunnell, Candace J. Goodson, Evan K. Pease, Sheng-Chiang Lee, and S.K. Remillard, "Even and Odd Order Nonlinearity from Superconductive Microstrip Lines," IEEE Trans. on Applied Superconductivity, Vol. 21, no. 3, pp. 595-598, (2011).
Annelle Eben (presenting author) and S.K. Remillard, Localized and Synchronous Measurement of 2nd and 3rd Order Nonlinearity in Superconductive Transmission Line Resonators, American Physical Society, March Meeting, Dallas, TX, March, 2011.
Can you measure the resistance of a superconductor? If so, does the resistance have an influence on devices fabricated with superconductors? Our microwave superconductivity research is following two directions: