Quadratic Fermi node in a 3D strongly correlated semimetal

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Strong spin-orbit coupling (SOC) and electron-electron interactions drive exotic electronic states.
• 5d transition metal iridium oxides are key materials in this emerging field.
• Understanding the interplay of strong SOC and electron correlations is crucial.

Purpose of the Study:

• To investigate the electronic properties of pyrochlore iridate Pr2Ir2O7.
• To identify and characterize novel topological electronic states.
• To explore the potential for realizing correlated topological phases.

Main Methods:

• Angle-resolved photoemission spectroscopy (ARPES) for electronic structure determination.
• First-principles calculations (e.g., DFT) for theoretical validation.
• Symmetry analysis to understand topological protection.

Main Results:

• Identification of a non-trivial electronic state with a single-point Fermi node in Pr2Ir2O7.
• The Fermi node is protected by cubic and time-reversal symmetries.
• Evidence for non-Fermi liquid behavior due to quadratic dispersion and strong Coulomb interactions.

Conclusions:

• Pr2Ir2O7 hosts a unique symmetry-protected topological state.
• This material serves as a parent compound for exploring other correlated topological phases.
• Potential applications in topological Mott insulators, Weyl semimetals, and quantum Hall effects.