High-pressure study of ${\mathrm{Bi}}_2$${\mathrm{Sr}}_2$${\mathrm{CaCu}}_2$${\mathrm{O}}_8$ single crystals

We report measurements of the in-plane resistivity (${\mathrm{\rho }}_{\mathit{a}\mathit{b}}$) and out-of-plane resistivity (${\mathrm{\rho }}_{\mathit{c}}$) on a ${\mathrm{Bi}}_2$ ${\mathrm{Sr}}_2$ ${\mathrm{CaCu}}_2$ ${\mathrm{O}}_8$ high-temperature superconducting single crystal under hydrostatic pressure up to 20 kbar. ${\mathrm{\rho }}_{\mathit{a}\mathit{b}}$ has an initial derivative d(ln${\mathrm{\rho }}_{\mathit{a}\mathit{b}}$)/dP of -0.75% ${\mathrm{kbar}}^{\mathrm{-}1}$, while ${\mathrm{\rho }}_{\mathit{c}}$ depends much more strongly on pressure, d(ln${\mathrm{\rho }}_{\mathit{a}\mathit{b}}$)/dP≊-4.0% ${\mathrm{kbar}}^{\mathrm{-}1}$. The superconducting transition temperature (${\mathit{T}}_{\mathit{c}}$) in both configurations increases monotonically by +0.15 K/kbar in the pressure range covered.