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：2019
卷号：116
期号：41
页码：20333-20338
DOI：10.1073/pnas.1910293116
出版社：The National Academy of Sciences of the United States of America
摘要：Physics of the quantum critical point is one of the most perplexing topics in current condensed-matter physics. Its conclusive understanding is forestalled by the scarcity of experimental systems displaying novel aspects of quantum criticality. We present comprehensive experimental evidence of a magnetic field-tuned tricritical point separating paramagnetic, antiferromagnetic, and metamagnetic phases in the compound CePtIn 4 . Analyzing field variations of its magnetic susceptibility, magnetoresistance, and specific heat at very low temperatures, we trace modifications of the antiferromagnetic structure of the compound. Upon applying a magnetic field of increasing strength, the system undergoes metamagnetic transitions which persist down to the lowest temperature investigated, exhibiting first-order–like boundaries separating magnetic phases. This yields a unique phase diagram where the second-order phase transition line terminates at a tricritical point followed by 2 first-order lines reaching quantum critical end points as T → 0. Our findings demonstrate that CePtIn 4 provides innovative perspective for studies of quantum criticality..
关键词：quantum critical end points ; metamagnetic transition ; antiferromagnetic ordering
