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

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 do...

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Bibliographic Details
Main Author: Bahr, Daniel
Other Authors: Van Harlingen, Dale J., Bezryadin, Alexey, Fradkin, Eduardo H., Chemla, Yann R.
Language:English
Published: 2011
Subjects:
IPY
Online Access:http://hdl.handle.net/2142/26013
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Summary: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. Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2011-07-14T15:41:59Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Dan Thesis.tex: 119323 bytes, checksum: fac659024d6de4974dd061cee6a8bf53 (MD5) Bahr_Daniel.pdf: 4637834 bytes, checksum: 66f3e7185274063f69051d97528d1475 (MD5) Made available in DSpace on 2011-08-25T22:08:54Z (GMT). No. of bitstreams: 3 Bahr_Daniel.pdf: 4637806 bytes, checksum: c711153371ed571ccb69df750fdc03e2 (MD5) license.txt: 4058 bytes, checksum: c55c812b613df3a9c4cabc90573c090f (MD5) Dan Thesis.tex: 119323 bytes, checksum: fac659024d6de4974dd061cee6a8bf53 (MD5)