2015年3月18日（周三）上午10點，量子物質科學協同創新中心“大師講堂”第六講／清華海外名師講堂第174講：



報告題目：	Correlations, Fluctuations, and Disorder at Chromium’s Quantum Phase Transition
報告人：	Dr. Thomas F. Rosenbaum, President of California Institute of Technology
報告時間：	2015-3-18 10:00
報告地點：	理科樓鄭裕彤大講堂
摘要：	We use hydrostatic pressure to suppress the magnetism in elemental chromium, a simple cubic metal that demonstrates a subtle form of itinerant antiferromagnetism, formally equivalent to the Bardeen-Cooper-Schrieffer (BCS) state in superconductors. By directly measuring the associated charge order with x-rays in a diamond anvil cell at low temperature, we reveal a phase transition at pressures ~ 10 GPa that destroys the BCS-like state while preserving the strong magnetic interaction between itinerant electrons and holes. Complementary transport results on both Cr and Cr doped with V expose a crossover to a narrow, fluctuation-dominated quantum critical regime. Cr is unique among stoichiometric magnetic metals studied to date in that its quantum phase transition is continuous in nature. This opens up experimental access to the naked quantum singularity, and a direct probe of the competition between conventional and exotic order in a theoretically tractable material.
個人簡介：	On July 1, 2014, Thomas F. Rosenbaum took office as Caltech’s ninth president. He is the Sonja and William Davidow Presidential Chair and Professor of Physics. Dr. Rosenbaum was formerly the John T. Wilson Distinguished Service Professor of Physics at the University of Chicago, where he served as the University's provost for seven years. As Chicago's provost, he had responsibility for a broad range of institutions and intellectual endeavors across the sciences, arts, and professional schools. He has been deeply engaged with Argonne National Laboratory as the University's vice president for research and for Argonne National Laboratory from 2002 to 2006 and as a member of its Board of Governors. Dr. Rosenbaum is an expert on the quantum mechanical nature of materials—the physics of electronic, magnetic, and optical materials at the atomic level—that are best observed at temperatures near absolute zero. He conducted research at Bell Laboratories and at IBM Watson Research Center before he joined the University of Chicago faculty. Dr. Rosenbaum is an elected fellow of the American Physical Society, the American Association for the Advancement of Science, and the American Academy of Arts and Sciences. Dr. Rosenbaum received his bachelor's degree in physics with honors from Harvard University and an MA and PhD in physics from Princeton University.

大師講堂第六講: Correlations, Fluctuations, and Disorder at Chromium’s Quantum Phase Transition

2015年3月18日（周三）上午10點，量子物質科學協同創新中心“大師講堂”第六講／清華海外名師講堂第174講：