Dresden 2009 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 28: Electronic Properties I

MM 28.5: Vortrag

Mittwoch, 25. März 2009, 11:15–11:30, IFW D

Photoemission insight into heavy-fermion behavior at the nanoscale — •Denis Vyalikh¹, Steffen Danzenbächer¹, Yuri Kucherenko², Cornelius Krellner³, Christoph Geibel³, Serguei Molodtsov¹, and Clemens Laubschat¹ — ¹Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden, Germany — ²Institute of Metal Physics, National Academy of Sciences of Ukraine, UA-03142 Kiev, Ukraine — ³Max-Planck-Institut für Chemische Physik Fester Stoffe, Nothnitzer Strasse 40, D-01187 Dresden, Germany

We unraveled the hybridization phenomenon between f- and d- states at the Fermi level in the YbRh₂Si₂ (YRS) heavy-fermion material. The intriguing point is that upon electron doping the hybridization strength can be systematically tuned. It is demonstrated that gradual deposition of silver atoms onto atomically clean YRS-surface leads to charge transfer from the Ag 5s into the Rh 4d bands substantially changing the energetical overlap of these states and, consequently, the hybridization strength. Another fascinating point is that silver atoms do not penetrate deep inside the crystal, consecutive forming well ordered monolayer’s structure. It is an evidence that observed tunable hybridization appears only in the surface region. Then it should reveal its own properties, like heavy-fermion behavior, which can be rather different from the bulk.