양자물질초전도연구실에서 스위스 PSI에 재직하는 Kenzelmann 교수님을 초청하여 아래와 같이 세미나를 개최합니다.

학과 구성원 여러분의 많은 참석을 부탁드립니다.

○ 일시: 2018년 3월 2일(금) 오전 11:00

○ 장소: 7th floor in Samsung Library

○ 연사: Prof. Michel Kenzelmann from Paul Scherrer Institut (Swiss)

○ Title: Evolving magnetic interactions near a Kondo breakdown

○ Abstract: Exchange interactions in heavy-fermion materials can trigger complex magnetic phases that
arise from localized or itinerant electrons. It is an open question how magnetic order is
affected when the Fermi surface topology is altered upon hybridization of local electronic
states with the conduction band. Here we study the evolution of magnetic order in the series
Nd1−xCexCoIn5 that features a Kondo breakdown within an antiferromagnetic phase. We
find a transition between two distinct magnetic phases that is detached from the emergence
of heavy-bands. This demonstrates that the magnetism and the Kondo coupling are governed by
different energy scales, in complete agreement with theory that predicts two separate
critical points. Close to the magnetic critical point, however, we find that the magnetic
structure changes symmetry. Our results demonstrate that the magnetic interactions change with
increasing electronic itineracy, and that theories need to include magnetic interactions that
evolve with the size of the Fermi surface.