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Back Cover: Microwave spectroscopy on heavy‐fermion systems: Probing the dynamics of charges and magnetic moments (Phys. Status Solidi B 3/2013)
Author(s) -
Scheffler Marc,
Schlegel Katrin,
Clauss Conrad,
Hafner Daniel,
Fella Christian,
Dressel Martin,
Jourdan Martin,
Sichelschmidt Jörg,
Krellner Cornelius,
Geibel Christoph,
Steglich Frank
Publication year - 2013
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201390007
Subject(s) - condensed matter physics , fermion , physics , spectroscopy , charge carrier , relaxation (psychology) , microwave , spin (aerodynamics) , superconductivity , quantum mechanics , psychology , social psychology , thermodynamics
The electronic properties of heavy‐fermion metals are governed by mobile charge carriers with drastically enhanced effective masses. Correspondingly, the characteristic energy scales of their optical response are much lower than for conventional metals: the transport relaxation of heavy fermions can be as low as a few GHz. Signatures of heavy‐fermion superconductivity and quantum criticality are also found or at least expected in this frequency range. To probe these charge dynamics at extremely low frequencies, novel techniques of microwave spectroscopy have to be employed. As described by Scheffler et al. ( pp. 439–449 ), devices based on planar microwave transmission lines are a powerful approach for this goal. Such experiments reveal the frequency‐dependent conductivity (i.e. the charge response), but they can also be used to study spin dynamics via electron spin resonance (ESR). This opens new possibilities to experimentally explore the spin dynamics of the heavy‐fermion material YbRh 2 Si 2 throughout its phase diagram including the vicinity of the quantum‐critical point.