Design and discovery of heavy fermion superconductors and semiconductors


Cedomir Petrovic
Brookhaven National Laboratory

Time and Place

Thursday, 13 March 2014 - 11:00am
CSEC Seminar Room


Design and Discovery of Heavy Fermion Superconductors and Semiconductors Cedomir Petrovic Condensed Matter Physics, Brookhaven National Laboratory Heavy fermion superconductors and semiconductors have been attracting considerable interest in the past several decades whereas new materials have been the driving force in the field [1-4]. One of the main points of interest has been the proximity to magnetic ground states, i.e. the possibility that superconducting and semiconducting gaps are driven by or related to magnetic interactions [5-6]. In this talk I will discuss two model materials: heavy fermion superconductor family CeMIn5 (M=Rh,Ir,Co), and FeSb2 - a correlated electron semiconductor similar to Kondo Insulators. The CeMIn5 family of quasi two dimensional heavy fermions has emerged as one of the primary clean model materials where large effective masses due to Abrikosov-Suhl resonance interplay with magnetic and superconducting states [7-9]. I will present CeMIn5 in the historical context, progressing from the discovery of this superconducting family, touching upon quantum criticality and ending with some recent results. In the case of FeSb2 I will address the similarity and difference with Kondo Insulators [10], structural and thermoelectric properties of crystals with and without Metal-Insulator transition [11] and unconventional metallic states induced by Te substitution [12]. References: [1] Phys. Rev. Lett. 43, 1892 (1979) [2] Science 239, 33 (1988) [3] Phys. Rev. Lett. 71, 1748 (1993) [4] Nature 450, 1177 (2007) [5] Nature 394, 22 (1998) [6] Phys. Rev. Lett. 69, 490 (1992) [7] Phys. Rev. Lett. 84, 4986 (2000) [8] Europhys. Lett. 53, 354 (2001) [9] J. Phys. Cond. Matter 13, L337 (2001) [10] Phys. Rev. B 72, 045103