Multiscale Quantum Criticality Driven by Kondo Lattice Coupling in Pyrochlore Systems.

Area of Science:

• Condensed Matter Physics
• Quantum Materials Science

Background:

• Pyrochlore oxides (A$_{2}$B$_{2}$O$_{7}$) host rare-earth local moments and 5d conduction electrons.
• These systems are platforms for exotic quantum many-body states, including U(1) quantum spin liquids and non-Fermi liquids.

Purpose of the Study:

• Investigate emergent quantum phases and transitions driven by Kondo lattice coupling.
• Analyze the interplay between Kondo coupling and long-range Coulomb interactions.

Main Methods:

• Renormalization group (RG) method applied to pyrochlore models.
• Theoretical investigation of phase transitions and critical behaviors.

Main Results:

• Weak Kondo coupling leads to a fractionalized semimetal phase.
• Increasing Kondo coupling drives transitions to fractionalized Fermi surface and ferromagnetic states.
• Competition between Kondo coupling and Coulomb interactions dictates phase stability and symmetry breaking.

Conclusions:

• Pyrochlore systems display rich phase diagrams governed by coupled quantum ground states.
• Observed transitions and critical behaviors have implications for experimental systems like Pr$_{2}$Ir$_{2}$O$_{7}$.