Hsu Yu-Te, Hartstein Máté, Davies Alexander J, Hickey Alexander J, Chan Mun K, Porras Juan, Loew Toshinao, Taylor Sofia V, Liu Hsu, Eaton Alexander G, Le Tacon Matthieu, Zuo Huakun, Wang Jinhua, Zhu Zengwei, Lonzarich Gilbert G, Keimer Bernhard, Harrison Neil, Sebastian Suchitra E
Cavendish Laboratory, Cambridge University, Cambridge CB3 0HE, United Kingdom.
Pulsed Field Facility, Los Alamos National Laboratory, Los Alamos, NM 87545.
Proc Natl Acad Sci U S A. 2021 Feb 16;118(7). doi: 10.1073/pnas.2021216118.
A central question in the underdoped cuprates pertains to the nature of the pseudogap ground state. A conventional metallic ground state of the pseudogap region has been argued to host quantum oscillations upon destruction of the superconducting order parameter by modest magnetic fields. Here, we use low applied measurement currents and millikelvin temperatures on ultrapure single crystals of underdoped [Formula: see text] to unearth an unconventional quantum vortex matter ground state characterized by vanishing electrical resistivity, magnetic hysteresis, and nonohmic electrical transport characteristics beyond the highest laboratory-accessible static fields. A model of the pseudogap ground state is now required to explain quantum oscillations that are hosted by the bulk quantum vortex matter state without experiencing sizable additional damping in the presence of a large maximum superconducting gap; possibilities include a pair density wave.
欠掺杂铜酸盐中的一个核心问题涉及到赝能隙基态的本质。有人认为，赝能隙区域的传统金属基态在适度磁场破坏超导序参量时会出现量子振荡。在此，我们对欠掺杂[化学式：见原文]的超纯单晶施加低测量电流并在毫开尔文温度下进行研究，以揭示一种非常规的量子涡旋物质基态，其特征为在高于实验室可达到的最高静态场时电阻率消失、磁滞以及非欧姆电输运特性。现在需要一个赝能隙基态模型来解释由体量子涡旋物质态所呈现的量子振荡，且在存在较大最大超导能隙的情况下不会经历可观的额外阻尼；可能的情况包括配对密度波。
