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arXiv · 1906.06823

Topological Phase Transition in an Archetypal f-electron Correlated System: Ce

Junwon Kim·Dongchoon Ryu·Chang-Jong Kang·Kyoo Kim·Hongchul Choi·T. -S. Nam·B. I. Min
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Abstract

A typical f-electron Kondo lattice system Ce exhibits the well-known isostructural transition, the so-called gamma-alpha transition, accompanied by an enormous volume collapse. Most interestingly, we have discovered that a topological-phase transition also takes place in elemental Ce, concurrently with the gamma-alpha transition. Based on the dynamical mean-field theory approach combined with density functional theory, we have unravelled that the non-trivial topology in alpha-Ce is driven by the f-d band inversion, which arises from the formation of coherent 4f band around the Fermi level. We captured the formation of the 4f quasi-particle band that is responsible for the Lifshitz transition and the non-trivial Z2 topology establishment across the phase boundary. This discovery provides a concept of 'topology switch' for topological Kondo systems. The 'on' and 'off' switching knob in Ce is versatile in a sense that it is controlled by available pressure (around 1 GPa) at room temperature.

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Junwon Kim, Dongchoon Ryu, Chang-Jong Kang, Kyoo Kim, Hongchul Choi, T. -S. Nam, B. I. Min. 2019-06-17. Topological Phase Transition in an Archetypal f-electron Correlated System: Ce. https://doi.org/10.1103/physrevb.100.195138

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