Abstract
In solids containing elements with f-orbitals, the interaction between f-electron spins and those of itinerant electrons leads to the development of low-energy fermionic excitations with a heavy effective mass. These excitations are fundamental to the appearance of unconventional superconductivity observed in actinide- and lanthanide-based compounds. We use spectroscopic mapping with the scanning tunneling microscope to detect the emergence of heavy excitations with lowering of temperature in Ce- and U-based heavy fermion compounds. We demonstrate the sensitivity of the tunneling process to the composite nature of these heavy quasiparticles, which arises from quantum entanglement of itinerant conduction and f-electrons. Scattering and interference of the composite quasiparticles is used in the Cebased compounds to resolve their energy-momentum structure and to extract their mass enhancement, which develops with decreasing temperature. Finally, by extending these techniques to much lower temperatures, we investigate how superconductivity, with a nodal d-wave character, develops within a strongly correlated band of composite excitations.
Original language | English (US) |
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Article number | 061008 |
Journal | Journal of the Physical Society of Japan |
Volume | 83 |
Issue number | 6 |
DOIs | |
State | Published - Jun 15 2014 |
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy