MIT Libraries logoDSpace@MIT

MIT
View Item 
  • DSpace@MIT Home
  • MIT Libraries
  • MIT Theses
  • Doctoral Theses
  • View Item
  • DSpace@MIT Home
  • MIT Libraries
  • MIT Theses
  • Doctoral Theses
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Verification of d-wave pairing symmetry by microwave intermodulation distortion measurements in yttrium barium copper oxide

Author(s)
Park, Sang-Hoon, Ph. D. Massachusetts Institute of Technology
Thumbnail
DownloadFull printable version (6.338Mb)
Other Contributors
Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.
Advisor
Daniel E. Oates and Terry P. Orlando.
Terms of use
M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582
Metadata
Show full item record
Abstract
We report measurements of the temperature and power dependence of the microwave frequency intermodulation distortion (IMD) in high quality pulsed laser deposition (PLD) Yttrium Barium Copper Oxide (YBCO) on LaAlO3 substrate. A low-temperature (T < 30 K) increase in IMD is the observation of an upturn of the nonlinear coefficient of the quadratic field dependence of the penetration depth. This IMD upturn is limited by the nonlinear Meissner effect that has been predicted for d-wave high-T, superconductors. Various amounts of IMD increase are observed for different films with impurity (Ni, Zn and Ca) doping and other defects. The demonstration of the IMD upturn and the nonlinear Meissner effect were possible because the IMD measurement is an extremely sensitive method to detect the penetration depth change at even less than 0.01 nm. IMDs from various samples tend to merge at a single universal value at 0 K regardless of disorder, defects, and impurities due to the node singularity at 0 K. There is a similar converging trend in IMD towards the transition temperature T, due to the quasiparticle thermal excitation and depletion of superelectrons. It is most likely that IMD has both intrinsic and extrinsic contributions.
 
(cont.) The 1/T2 divergence at low T of the IMD was theoretically predicted and confirmed with high quality PLD YBCO on LaA103 substrate from below 30 K. We found that Ni-doped YBCO gave an IMD increase comparable to high quality PLD YBCO. This finding agrees with the evidence that Ni (magnetic impurity) does not destroy superconductivity and preserves d-wave symmetry as shown in scanning tunneling microscope experiments. The off-the-resonance excitation experiment indicates that the response time scale of nonlinearity in IMD generation is not affected by the magnitude of two-tone separation [delta]f = f2 - fl in YBCO on LaA103 substrate. But, at low temperature ([delta] < 20 K) and low output power at fundamental frequency (Pit < -30 dBm), the response time scale slows down IMD generation as the [delta]f increases in YBCO on MgO substrate.
 
Description
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.
 
Includes bibliographical references (p. 113-119).
 
Date issued
2004
URI
http://hdl.handle.net/1721.1/39732
Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Publisher
Massachusetts Institute of Technology
Keywords
Electrical Engineering and Computer Science.

Collections
  • Doctoral Theses

Browse

All of DSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

My Account

Login

Statistics

OA StatisticsStatistics by CountryStatistics by Department
MIT Libraries
PrivacyPermissionsAccessibilityContact us
MIT
Content created by the MIT Libraries, CC BY-NC unless otherwise noted. Notify us about copyright concerns.