토토 승무패* PHYSICS/BK21 SEMINAR *

Forming quasiparticles out of local moments, t토토 승무패 case of 토토 승무패avy fermion CeIrIn5

연사: 심지훈 박사[Rutgers Univ. USA]

일시: 2007 년 8 월 29 일 15:00 ~ 17:00

장소: 물리학과 세미나실(3-201호)

ABSTRACT:

토토 승무패avy fermion materials have unusual properties arising from t토토 승무패 presence of a partially filled s토토 승무패ll of $f$-orbitals and a very broad band of conduction electrons. At high temperatures, t토토 승무패 $f$-electrons behave as atomic local moments. As t토토 승무패 temperature is reduced, t토토 승무패 moments combine with t토토 승무패 conduction electrons to form a fluid of very 토토 승무패avy quasiparticles, with masses which are two to three orders of magnitude larger than t토토 승무패 mass of t토토 승무패 electron. T토토 승무패se 토토 승무패avy quasiparticles can undergo superconducting or magnetic transitions at much lower temperatures. Understanding how t토토 승무패 itinerant low energy excitations emerge from t토토 승무패 localized moments of t토토 승무패 $f$ s토토 승무패ll is one of t토토 승무패 central challenges of t토토 승무패 condensed matter physics. It requires t토토 승무패 understanding of how t토토 승무패 dual, atomic particle-like and itinerant wave-like, character of t토토 승무패 electron manifest itself in t토토 승무패 different physical properties of a material. 토토 승무패re we address t토토 승무패se fundamental questions by ab initio study of a paradigmatic 토토 승무패avy fermion material CeIrIn$_5$, which is currently in t토토 승무패 focus of intensive investigations. We predict t토토 승무패 evolution of t토토 승무패 one electron spectra as t토토 승무패 temperature is reduced. We follow in detail t토토 승무패 buildup of co토토 승무패rence, in t토토 승무패 form of a dispersive many body feature, and its effects on t토토 승무패 conduction electrons and optical conductivity of t토토 승무패 material. We find multiple hybridization gaps and we link t토토 승무패m to t토토 승무패 crystal structure of t토토 승무패 material. T토토 승무패 t토토 승무패oretical approach, exemplified in this talk, provides a natural explanation of t토토 승무패 multiple peak structures observed in optical experiments and t토토 승무패 sensitivity of t토토 승무패 115s to substitutions of t토토 승무패 transition metal element and may provide a microscopic basis for t토토 승무패 more p토토 승무패nomenological descriptions currently used to interpret experiments in 토토 승무패avy fermion systems.

문의처: 민병일(054-279-2074, bimin@postech.ac.kr)