University of Illinois Urbana-Champaign

Probing the chiral domain structure and dynamics in SR2RUO4 with nanoscale Josephson junctions

Bahr, Daniel

Content Files
Bahr_Daniel.pdf

Permalink

https://hdl.handle.net/2142/26013

Description

Title
Probing the chiral domain structure and dynamics in SR2RUO4 with nanoscale Josephson junctions
Author(s)
Bahr, Daniel
Issue Date
2011-08-25T22:08:54Z
Director of Research (if dissertation) or Advisor (if thesis)
Van Harlingen, Dale J.
Doctoral Committee Chair(s)
Bezryadin, Alexey
Committee Member(s)
  • Van Harlingen, Dale J.
  • Fradkin, Eduardo H.
  • Chemla, Yann R.
Department of Study
Physics
Discipline
Physics
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Date of Ingest
2011-08-25T22:08:54Z
Keyword(s)
  • Sr2RuO4
  • chiral domains
  • Josephson Interferometry
  • Josephson Junctions
Abstract
Previous work on Sr2RuO4 has shown that the superconducting state is unconventional with an order parameter symmetry of px ipy. Measurements using Josephson Interferometry have shown evidence for chiral order parameter domains on the order of 1 m in size. To further search for signatures of these domains we have fabricated Josephson junctions on clean Sr2RuO4 single crystals (Tc=1.5 K) ranging from 500 nm to 4 m wide. Using an applied magnetic eld, we modulated the critical current of the junctions to make phasesensitive measurements of the order parameter of the p-wave superconductor. We observed critical current characteristics consistent with single and multiple domains being present in the junctions. We also observed hysteresis e ects in the junctions similar to previous experimental and theoretical work. We explored eld cooling e ects in the junctions that showed possible domain wall movement along the face of the junction. We also observed switches in the critical current that are not described currently by known theory and could be an indication of vertically oriented domains. We found that our smallest (500 nm) junctions consistently showed characteristics consistent with single domain junctions and that our results are consistent with 1 u m domains.
Graduation Semester
2011-08
Permalink
http://hdl.handle.net/2142/26013
Copyright and License Information
Copyright 2011 Daniel Bahr

Owning Collections

Graduate Dissertations and Theses at Illinois PRIMARY
Graduate Theses and Dissertations at Illinois
Dissertations and Theses - Physics
Dissertations in Physics