{'fraction_non_alphanumeric': 0.028727770177838577, 'fraction_numerical': 0.004103967168262654, 'mean_word_length': 4.545454545454546, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Singular Fermi liquid behavior in the underscreened Kondo model

Using the Schwinger boson spin representation, we reveal a new aspect to the physics of a partially screened magnetic moment in a metal, as described by the spin-S Kondo model. We show that the residual ferromagnetic interaction between a partially screened spin and the electron sea destabilizes the Landau Fermi liquid, forming a singular Fermi liquid with a 1/[T ln 4 (T K /T)] divergence in the low-temperature specific heat coefficient C V /T. A magnetic field B tunes this system back into Landau Fermi liquid with a Fermi temperature proportional to B ln 2 (T K /B). We discuss a possible link with field-tuned quantum criticality in heavy-electron materials.