Quasiparticle scattering spectroscopy ( QPS ) of Kondo lattice

Submitted for the MAR13 Meeting of The American Physical Society Quasiparticle scattering spectroscopy (QPS) of Kondo lattice heavy fermions1 L.H. GREENE, S.M. NARASIWODEYAR, P. BANERJEE, W.K. PARK, University of Illinois at Urbana-Champaign, E.D. BAUER, P.H. TOBASH, R.E. BAUMBACH, F. RONNING, J.L. SARRAO, J.D. THOMPSON, Los Alamos National Laboratory — Point-contact spectroscopy (PCS) is a powerful technique to study electronic properties via measurements of non-linear currentvoltage characteristic across a ballistic junction. It has been frequently adopted to investigate novel and/or unconventional superconductors by detecting the energydependent Andreev scattering. PCS of non-superconducting materials has been much rarely reported. From our recent studies on heavy fermions [1], we have frequently observed strongly bias-dependent and asymmetric conductance behaviors. Based on a Fano resonance model in a Kondo lattice [2], we attribute them to energy-dependent quasiparticle scattering off hybridized renormalized electronic states, dubbing it QPS. We will present our QPS results on several heavy-fermion systems and discuss QPS as a novel technique to probe the bulk spectroscopic properties of the electronic structure. For instance, it reveals that the hybridization gap in URu2Si2 opens well above the hidden order transition [1]. [1] W. K. Park et al., PRL 108, 246403 (2012); ibid., 100, 177001 (2008). [2] M. Maltseva, M. Dzero, P. Coleman, PRL 103, 206402 (2009). 1The work at UIUC is supported by the U.S. DOE under Award No. DE-FG0207ER46453 and the NSF DMR 12-06766, and the work at LANL is carried out under the auspices of the U.S. DOE, Office of Science. Laura Greene University of Illinois at Urbana-Champaign Date submitted: 14 Nov 2012 Electronic form version 1.4