Average kinetic energy density of Cooper pairs above Tc in YBa2Cu3O7-x , Bi2Sr2CaCu2O8+δ , and Nb
Abstract
We have obtained isofield curves for the square root of the average kinetic energy density of the superconducting state for three single crystals of underdoped YBa2Cu3O7-x , an optimally doped single crystal of Bi2Sr2CaCu2O8+δ , and Nb. These curves, determined from isofield magnetization versus temperature measurements and the virial theorem of superconductivity, probe the order parameter amplitude near the upper critical field. The striking differences between the Nb and the high- Tc curves clearly indicate for the latter cases the presence of a unique superconducting condensate below and above Tc .
- Publication:
-
Physical Review B
- Pub Date:
- October 2007
- DOI:
- 10.1103/PhysRevB.76.132502
- arXiv:
- arXiv:0710.2459
- Bibcode:
- 2007PhRvB..76m2502S
- Keywords:
-
- 74.25.Bt;
- 74.25.Ha;
- 74.62.-c;
- 74.72.Bk;
- Thermodynamic properties;
- Magnetic properties;
- Transition temperature variations;
- Y-based cuprates;
- Condensed Matter - Superconductivity;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- PRB 76, 132502 (2007)