Condensed Matter Seminar "Fermi Surface Reconstruction in Nd-doped CeCoIn5"

Thursday, February 7, 2019 - 11:30am

Speaker(s): 
Elizabeth L. Green (Helmholtz-Zentrum Dresden-Rossendorf)

CeCoIn5, one of the most well-studied heavy fermion systems, exhibits a novel field-induced superconducting state above 10T for B||a known as the Q-phase. Recent neutron scattering measurements show a similar Q-vector for the 5% Nd-doped CeCoIn5 at zero applied magnetic field which has initiated intense theoretical and experimental work on this doping series. In this talk I will present de Haas-van Alphen (dHvA) effect measurements which demonstrate a drastic Fermi surface reconstruction between 2 and 5% Nd-doping levels is responsible for the emergence of this unconventional superconducting state. The cylindrical Fermi surface develops a quasi-three-dimensional topology with increased doping levels thus reducing the likelihood of an enhanced nesting scenario, previously given as a possible explanation for the presence of the Q-phase. Effective masses remain unchanged up to 10% Nd, indicating the presence of a spin density wave type of quantum critical point. In addition, I will present evidence that by substituting Ce with Nd the electronic pairing potential is altered. These results highlight the need for additional experiments and further theoretical calculations to accurately model this unique system.

Physics 298

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