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Pressure-driven quantum criticality in iron-selenide superconductors
Jing Guo1, Xiao-Jia Chen, Jianhui Dai
1Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
Physical Review Letters
|September 26, 2012
Summary
We found a pressure-induced quantum critical transition in iron-selenide superconductors. This transition involves changes in electronic behavior and magnetism near where superconductivity disappears.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Materials
Background:
- Superconductivity in iron-selenides is often linked to magnetism.
- Understanding quantum critical points is crucial for novel material properties.
Purpose of the Study:
- To investigate the quantum critical behavior of K0.8Fe(x)Se2 superconductors under pressure.
- To explore the relationship between magnetism, electronic states, and superconductivity.
Main Methods:
- In situ high-pressure electrical transport measurements.
- In situ high-pressure X-ray diffraction.
- Utilized diamond anvil cells for extreme pressure conditions.
Main Results:
- Observed a pressure-induced quantum critical transition in K0.8Fe(x)Se2 (x = 1.7, 1.78) at 9.2-10.3 GPa.
- Identified transitions from metallic Fermi liquid to non-Fermi liquid behavior.
- Observed transitions from antiferromagnetism to paramagnetism, coinciding with superconductivity suppression.
Conclusions:
- The quantum critical transition in these iron-selenide superconductors exhibits a unique mechanism.
- The interplay between magnetism, electronic states, and superconductivity is key to understanding this phenomenon.
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