12th CEMS Colloquium

講演者

松田祐司（京都大学教授）

日程

2013年12月4日(水) 16:30～17:30

開催場所

理化学研究所　大河内記念ホール

講演タイトル

超伝導ドームに隠れた量子臨界点

講演概要

Whether a quantum critical point (QCP) lies beneath the superconducting dome has been a long-standing issue that remains unresolved in many classes of unconventional superconductors, notably cuprates, heavy fermion compounds and most recently iron-pnictides. The existence of a QCP may offer a route to understand: the origin of their anomalous non-Fermi liquid properties, the microscopic coexistence between unconventional superconductivity and magnetic or some exotic order, and ultimately the mechanism of superconductivity itself. The isovalent substituted iron-pnictide BaFe₂ (As_1−x P_x)₂ offers a new platform for the study of quantum criticality, providing a unique opportunity to study the evolution of the electronic properties in a wide range of the phase diagram. Recent experiments in BaFe₂ (As_1−xP_x)₂ have provided the first clear and unambiguous evidence of a second order quantum phase transition lying beneath the superconducting dome. Based on these results, a new phase diagram of iron-pnictide is discussed.