期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2014
卷号：111
期号：39
页码：14088-14093
DOI：10.1073/pnas.1413112111
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceTemperature-driven phase transitions, such as the melting of ice or the boiling of water, are a familiar part of daily life. Much less is known about the most extreme phase transitions, which happen only at zero temperature, where quantum fluctuations limit the stabilities of different collective ground states such as magnetic order and superconductivity. We report an experimental investigation of YFe2Al10, where planes of Fe atoms are naturally poised on the verge of ferromagnetic order, exactly at T = 0. The thermal, magnetic, and electrical transport properties in YFe2Al10 all diverge as T [->] 0, a process that can be reversed by magnetic fields in a way that is dictated by the underlying system energy. The absence of thermal fluctuations at T = 0 makes it possible to observe the inherently quantum mechanical nature of systems where the competition among correlations leads to different types of collective ground states. Our high precision measurements of the magnetic susceptibility, specific heat, and electrical resistivity in the layered compound YFe2Al10 demonstrate robust field-temperature scaling, evidence that this system is naturally poised without tuning on the verge of ferromagnetic order that occurs exactly at T = 0, where magnetic fields drive the system away from this quantum critical point and restore normal metallic behavior.
