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Evidence for a delocalization quantum phase transition without symmetry breaking in CeCoIn5.
Nikola Maksimovic1,2, Daniel H Eilbott1,2, Tessa Cookmeyer1,2
1Department of Physics, University of California, Berkeley, Berkeley, CA 94720, USA.
Science (New York, N.Y.)
|December 2, 2021
Summary
Researchers explored quantum phase transitions in unconventional superconductors like CeCoIn5. They found evidence of electron delocalization and Fermi surface changes, suggesting a new mechanism for high-temperature superconductivity without broken symmetry.
Area of Science:
- Condensed Matter Physics
- Quantum Materials
- Superconductivity
Background:
- Quantum phase transitions without broken symmetry are crucial for understanding high-temperature superconductivity.
- Unconventional superconductors like CeCoIn5 present a key area for studying these phenomena.
- The underlying mechanisms of superconductivity in these materials remain a significant challenge.
Purpose of the Study:
- To investigate the nature of the quantum critical point in the unconventional superconductor CeCoIn5.
- To explore transitions characterized by changes in Fermi surface volume without apparent symmetry breaking.
- To interpret anomalous transport behavior, specifically the Hall effect, within theoretical frameworks.
Main Methods:
- Theoretical analysis based on established theories of f-electron metals.
- Experimental measurement of the Hall effect to probe anomalous transport behavior.
- Characterization of electronic transitions involving Fermi surface volume changes.
Main Results:
- Identified a quantum critical point in CeCoIn5 associated with electron delocalization.
- Observed a transition connecting two Fermi surfaces of distinct volumes.
- Demonstrated that this transition occurs without any apparent broken symmetry.
Conclusions:
- The quantum critical point in CeCoIn5 is characterized by electron delocalization and Fermi surface reconstruction.
- A theoretical model involving spin and charge fractionalization explains the observed anomalous transport properties.
- This provides a potential mechanism for superconductivity not reliant on traditional symmetry breaking.
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