Wydarzenia

Seminarium Międzynarodowego Laboratorium Silnych Pól Magnetycznych i Niskich Temperatur PAN

Unconventional superconductivity and other quantum critical phenomena in f-electron systems (part III)

prof. Dariusz Kaczorowski

Institute of Low Temperature and Structure Research, Polish Academy of Sciences
International Laboratory of High Magnetic Fields and Low Temperatures

Since the spectacular discovery of the phenomenon in 1979, advanced experimental and theoretical studies on heavy-fermion superconductivity have continued to be at the very forefront of modern condensed matter physics. This is due to the special character of the superconducting state, which cannot be described in terms of the conventional theory of superconductivity, as well as due to a variety of unusual physical behavior observed in the normal state. The microscopic nature of all these anomalous phenomena originates from strong electronic correlations in metallic systems bearing localized magnetic moments. In recent years, significant progress has been made in understanding the fundamental mechanisms responsible for the simultaneous presence of magnetism and superconductivity (by a number of decades considered as entirely antagonistic). In consequence, the scenarios of competition, coexistence or sometimes even interplay of the two cooperative phenomena have been recognized. Nevertheless, a consistent universal theory of the heavy-fermion superconductivity that might account for all its intriguing aspects is still lacking. Furthermore, new experimental discoveries in the field often result in identification of novel scientific challenges.

In my two lectures at ILHMF&LT I shall briefly review the basic concepts of the physics of strongly correlated electron systems with the particular emphasis put on the formation of heavy-fermion ground states, quantum critical phenomena and unconventional magnetically-driven superconductivity. A historical overview of the main discoveries made in the area will be supplemented with our own results, recently obtained in our laboratories at ILT&SR PAS. Finally, an attempt will be made to address a few most challenging open questions in the relevant field.