Dynamics of Heavy Carriers in the Ferromagnetic Superconductor UGe2
DOI (if applicable)
Superconductivity and ferromagnetism in a number of uranium-based materials come from the same f-electrons with a relatively large effective mass, suggesting the presence of a band of heavy quasiparticles, whose nature is still a mystery. Here, UGe2 dynamics in both ferromagnetic and paramagnetic phases is studied employing high-field μ+SR spectroscopy. The spectra exhibit a doublet structure characteristic to formation of subnanometer-sized magnetic polarons. This model is thoroughly explored here and correlated with the unconventional physics of UGe2. The heavy-fermion behavior is ascribed to magnetic polarons; when coherent they form a narrow band, thus reconciling heavy carriers with superconductivity and itinerant ferromagnetism.
Storchak, V.G., Brewer, J.H., Eshchenko, D.G. et al. Jetp Lett. (2018) 107: 470. https://doi.org/10.1134/S0021364018080040