Pressure effects on the transition temperature and the magnetic field penetration depth in the pyrochlore superconductor RbOs_2O_6

TL;DR

This study investigates how hydrostatic pressure influences the transition temperature and magnetic penetration depth in the pyrochlore superconductor RbOs_2O_6, revealing a positive pressure effect on T_c but no change in penetration depth.

Contribution

The paper provides the first high-pressure magnetization measurements on RbOs_2O_6, showing a significant positive pressure effect on T_c and suggesting it behaves as an adiabatic BCS superconductor.

Findings

Pressure increases T_c with dT_c/dp = 0.090 K/kbar

No detectable pressure effect on magnetic penetration depth

Pressure shift of T_c comparable to underdoped cuprates

Abstract

We report magnetization measurements under high hydrostatic pressure in the newly discovered pyrochlore superconductor RbOs_2O_6 (T_c\simeq6.3K at p=0). A pronounced and {\it positive} pressure effect (PE) on T_c with dT_c/dp =0.090(1)K/kbar was observed, whereas no PE on the magnetic penetration depth \lambda was detected. The relative pressure shift of T_c [ dlnT_c/dp \simeq 1.5%/kbar] is comparable with the highest values obtained for highly underdoped high-temperature cuprate superconductors. Our results suggest that RbOs_2O_6 is an adiabatic BCS-type superconductor.