Temperature dependence of superfluid density in YBa2Cu3O7−δ and Y0.7Ca0.3Ba2Cu3O7−δ thin films: A doping dependence study of the linear slope

✍ Scribed by L.S. Lai; J.Y. Juang; K.H. Wu; T.M. Uen; Y.S. Gou

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 138 KB
• Volume: 432
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2005.07.014

✦ Synopsis

By using a microstrip ring resonator to measure the temperature dependence of the in-plane magnetic penetration depth k(T) in YBa 2 Cu 3 O 7Àd (YBCO) and Y 0.7 Ca 0.3 Ba 2 Cu 3 O 7Àd (Ca-YBCO) epitaxially grown thin films, the linear temperature dependence of the superfluid density q s /m * 1/k 2 (T) was observed from the under-to the overdoped regime at the temperatures below T T c % 0:3. For the underdoped regime of YBCO and Ca-YBCO thin films, the magnitude of the slope d(1/k 2 (T))/dT is insensitive to doping, and it can be treated in the framework of projected d-density-wave model. Combining these slope values with the thermal conductivity measurements, the Fermi-liquid correction factor a 2 from the Fermi-liquid model, suggested by Wen and Lee, was revealed here with various doping levels.