Abstract
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