Valence transition in topological Kondo insulator

Area of Science:

• Condensed Matter Physics
• Topological Materials Science

Background:

• Topological Kondo insulators exhibit unique electronic properties arising from the interplay of topology and strong electron correlations.
• Understanding valence transitions is crucial for characterizing the behavior of these complex materials.

Purpose of the Study:

• To investigate the valence transition mechanisms in three-dimensional topological Kondo insulators.
• To explore the influence of intra-atomic Coulomb correlation and temperature on these transitions.

Main Methods:

• Slave-boson analysis of the periodic Anderson model.
• Theoretical investigation incorporating intra-atomic Coulomb correlation effects.

Main Results:

• A first-order valence transition from Kondo to mixed valence state occurs with increasing local f-level, often coinciding with topological transitions.
• Temperature can induce a reverse valence transition from mixed valence to Kondo state, coupled with a topological transition.
• Antiferromagnetic transitions can shift from continuous to first-order, accompanied by discontinuous valence shifts.

Conclusions:

• The study elucidates novel valence and topological transition processes in topological Kondo insulators.
• These findings offer insights into thermal valence variations and magnetic transition-induced valence shifts in heavy-fermion systems.