Year: 2026
Type: preprint
Abstract: The partially disordered (PD) phase, in which magnetically ordered and Kondo-screened sites coexist, has been proposed as a possible ground state of geometrically frustrated heavy-fermion systems. We investigate its dynamical properties in the half-filled periodic Anderson model on a triangular lattice by calculating the dynamical spin susceptibility within the random-phase approximation built on a self-consistent Hartree-Fock solution. We show that successive quantum phase transitions from the Kondo-insulating phase to the PD phase and to a magnetically ordered phase are driven by the condensation of triplon modes originating predominantly from the Kondo-screened sites. In the PD phase, magnons and triplons coexist and hybridize, leading to characteristic level repulsion in the excitation spectrum. These results reveal how triplet excitations evolve into collective magnetic modes across the successive phase transitions and highlight the dynamical interplay between magnetic order and Kondo screening in frustrated heavy-fermion systems.
Source: arXiv (Cornell University)
Institutions: Waseda University, Technical University of Munich
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223664129