Ground state anomalies in SmB₆

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Samarium hexaboride (SmB₆) is a compelling correlated electron system.
• It is known for anomalous ground state properties and predicted topological surface states.
• Existing theories struggle to fully capture its complex electronic behavior.

Purpose of the Study:

• To investigate the electronic structure of SmB₆.
• To understand the origin of its anomalous ground state properties.
• To elucidate the factors contributing to its predicted topological surface states.

Main Methods:

• Density functional theory (DFT) calculations.
• Exploration of various exchange-correlation potentials.
• Inclusion of spin-orbit coupling and electron correlation effects (e.g., on-site Coulomb interaction, U).

Main Results:

• Optimized DFT parameters (exchange-correlation, spin-orbit coupling, electron correlation) accurately reproduce experimental spectral functions from angle-resolved photoemission spectroscopy (ARPES).
• Calculated Fermi surface shows characteristic electron and hole pockets with significant Sm 4f orbital contribution.
• Strong hybridization between Boron 2p and Samarium 4f orbitals is identified as crucial, alongside weaker Sm 5d contributions.

Conclusions:

• The study provides a robust theoretical framework for understanding SmB₆'s electronic structure.
• The findings highlight the critical role of Sm 4f and B 2p hybridization in SmB₆'s exotic physics.
• Results align with and support recent experimental observations from quantum oscillations and ARPES.