Pressure dependence of high-T_c superconductors

Abstract

We recently developed a method to derive the charge carrier concentration 6 (holes per planar copper atom) under pressure from the measured T_c and H_c2. The different behaviour of YBa₂Cu₄O₈, CaLaBaCu₃)₇ and other compounds can be understood from the difference in ∂δ/∂p using a model where T_c is quadratically dependent upon δ and where δ is linearly dependent upon pressure, as observed experimentally.

Key Words:

• High temperature superconductors
• critical temperature
• upper critical field