Placement Information
Year you started your placement
2019
Placement period
May – August, September – December
Supervisor’s name
Dirk Manske
Project Details
Overview
In superconductors, spontaneous U(1) symmetry breaking occurs at the transition to the superconducting state, which is reflected by a Mexican hat shaped free energy potential. Collective modes, corresponding to oscillations of the order parameter, arise as a result of this symmetry breaking. In particular, amplitude oscillations are known as the Higgs mode, in analogy to high energy physics. This mode is difficult to detect because it does not couple linearly to light. However, it was demonstrated that it can be excited and measured experimentally with ultrafast Terahertz spectroscopy. As this technique is relatively new, the exact excitation processes are not yet fully understood. In multiband superconductors, a relative phase mode, known as the Leggett mode, arises as a result of the interband coupling. The group I worked for theoretically investigates the excitation of these modes, as it has been shown that they can be used as a spectroscopic tool to better understand unconventional superconductivity.
Project objectives
It has been shown that impurity scattering is non-negligible when modeling the response of these modes. Thus, my project was to investigate the effects of impurity scattering on the Higgs and Leggett modes.
Research outcomes
Project status
Completed
Paul Froese – 2019 – Report
Paul Froese – 2019 – Poster
Paul Froese – 2019 – Talkwed
My Co-op Experience at MPI/ UTokyo
Why did you apply for this placement?
I was interested in doing a research coop, and was hoping to come to Germany as most of my family lives here. In particular I wanted to try theoretical research, as I am hoping to do something along those lines after I graduate.
What recommendations do you have for students who wish to participate in this exchange program?
I recommend looking at the different projects beforehand and doing some research to figure out which one truly interests you. Then, it is helpful to do some background research in the field so there is less catching up to do once you arrive.
Tell us about your travels and cultural experiences
Stuttgart is quite central within Europe, making it easy to travel to lots of places. I was able to do many trips to go hiking, visit family, and explore new cities with friends. However, by far the best and my favourite cultural aspect of living in Stuttgart is the pretzel.
Hiking in eastern Germany
Paris
Bavarian alps
The most important cultural experience