Pressure Studies on a High-$T_c$ Superconductor Pseudogap and Critical Temperatures

We report simultaneous hydrostatic pressure studies on the critical temperature $T_c$ and on the pseudogap temperature $T^{\ast }$ performed through resistivity measurements on an optimally doped high-$T_c$ oxide $H{g}_{0.82}R{e}_{0.18}B{a}_{2}C{a}_{2}C{u}_3{O}_{8+\delta }$. The resistivity is measured as function of the temperature for several different applied pressure below 1GPa. We find that both $T_c$ and $T^{\ast }$ increases linearly with the pressure. This result demonstrate that the well known intrinsic pressure effect on $T_c$ is also present at $T^{\ast }$ and both temperatures are originated by the same superconducting mechanism.