Competing ordered phases in URu2Si2: hydrostatic pressure and rhenium substitution
J R Jeffries1, N P Butch, B T Yukich
1Department of Physics and Institute for Pure and Applied Physical Sciences, University of California, San Diego, La Jolla, California 92093, USA.
Physical Review Letters
|February 1, 2008
Summary
A kink in the hidden order transition temperature of URu2-xRexSi2 was observed at 15 kbar. This pressure destroys superconductivity and alters the spin excitation gap and Fermi surface.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Materials
Background:
- URu2Si2 exhibits a unique "hidden order" (HO) phase.
- Understanding the interplay between HO, superconductivity, and electronic structure is crucial.
Purpose of the Study:
- Investigate the pressure dependence of the HO transition in URu2-xRexSi2.
- Clarify the relationship between HO, superconductivity, and Fermi surface topology under pressure.
Main Methods:
- Electrical resistivity measurements to determine transition temperatures and electronic properties.
- Analysis of spin excitation gaps and Fermi surface (FS) changes.
Main Results:
- A persistent kink in the HO transition temperature was observed at a critical pressure (Pc) of 15 kbar for 0 <= x <= 0.08.
- Superconductivity is destroyed at Pc.
- A change in the spin excitation gap magnitude and complete gapping of a portion of the FS occur at Pc.
Conclusions:
- The critical pressure Pc signifies a fundamental change in the electronic state of URu2-xRexSi2.
- Competition between the HO state and superconductivity influences the Fermi surface fraction.
