CNRS Université Paris-Sud 11



Rechercher

Sur ce site

Sur le Web du CNRS

CSNSM - UMR8609
Bâtiments 104 et 108
91405 Orsay Campus

+33 1 69 15 52 13
104 +33 1 69 15 50 08
108 +33 1 69 15 52 68
Mentions légales

Accueil > Séminaires > Séminaires passés > Seminaires de 2014 > An ARPES view of YbCo2Si2 - the stable-valent isoelectronic counterpart to the heavy-fermion YbRh2Si2

Monika Güttler (Dresden University of Technology, Germany)

An ARPES view of YbCo2Si2 - the stable-valent isoelectronic counterpart to the heavy-fermion YbRh2Si2

vendredi 16 mai, 10h, CSNSM Salle de réunion du Bât 108

Strongly correlated electron systems range among the most intensively studied materials in modern condensed matter physics such as the prominent high- Tc superconducting cuprates or heavy-fermion compounds containing 4f or 5f elements. ’Heavy fermions’ are quasiparticle excitations arising in Kondo lattices with strongly renormalized masses exceeding the free electron mass up to thousand or more times. These materials have attracted special interest, as the complex interplay between localized f states and itinerant conduction electrons often induces unusual states of matter in the vicinity of a quantum phase transition, which range from unconventional superconductivity to deviations from Fermi liquid behavior.

YbRh2Si2 is a prototypical mixed-valent heavy-fermion compound located very closely to an antiferromagnetic quantum critical point. Its valence and extremely weak magnetic ordering may be stabilized upon pressure or substitution of Rh with smaller Co atoms, leading eventually to the stable-valent isoelectronic compound Yb Co2 Si2. This talk focuses on the electronic structure of Yb Rh2 Si2 and its counterpart Yb Co2 Si2 as viewed by angle-resolved photoelectron spectroscopy (ARPES) at low temperature. Using YbCo2Si2 as a reference, a comparison of the Fermi surface topologies of both compounds identifies the Fermi surface of YbRh2Si2 clearly to be ’large’ in zero field above 10K, i.e., including the 4f degrees of freedom.

PDF

PDF - 65.9 ko
Affiche du séminaire