令和 ２年度（２０２０年度）第2回 物理教室談話会

題目	Exotic phenomena emerging from magnetic interactions
講師	Prof. Harald O. Jeschke (岡山大学　教授)
日時	16:20-17:30 November 20 (Friday), 2020
場所	The Lecture Room 21, Faculty of Science (2nd Floor)
概要	Superconductors are materials that conduct electrical currents without any resistive losses. This phenomenon already has significant technological applications, for example in hybrid magnets used for medical equipment. Superconductivity has the potential to revolutionize the energy infrastructure by eliminating energy losses. However, the fact that most materials only become superconducting at low or very low temperatures means that the expense of cooling so far limits the applicability of superconducting devices. Finding new and better superconducting materials requires a microscopic understanding of the mechanisms involved in superconductivity. In unconventional high temperature superconductors, magnetic pairing mechanisms are responsible for the formation of electron pairs which can be transported without resistance. We will discuss how the theoretical determination of magnetic interactions can lead to new insights. In a different class of materials, frustrated magnets, the magnetic interactions compete and prevent simple ordered magnetic ground states. As a consequence, exotic magnetic phases like a spin liquid can occur; in spin liquids, the magnetic moments interact strongly but never freeze even at lowest temperatures. Such phases are intensively investigated because they are candidates for technologies that could revolutionize computing - they could become important in quantum computers. We will show that determining magnetic interactions helps identify materials with exotic ground states.
世話人	市岡　優典（内線7806）