论文标题
超导高原
The Superconducting Plateau
论文作者
论文摘要
在轻度掺杂钛酸锶中的两个最新实验表明，超导临界温度在覆盖近三个数量级的一系列载体浓度中保持恒定。这种现象的重要性，特此称为超导高原，与著名的超导圆顶相媲美。戏剧性的经验证据对低兴奋剂的任何超导机制的任何提案都施加了严重的限制。我们分析了实验结果，以查看哪种类型的理论模型在此制度中适合。我们表明，低临界电流，缺乏磁性筛查和高临界场都与载体的较小动量有关，载体的势头较小，这是在低密度下预期的。我们通过引入“密度指数”来量化临界温度对密度的依赖性。我们讨论了量子关键点在高原形成中的作用，并评论需要更多实验数据。
Two recent experiments in lightly doped strontium titanate have shown that the superconducting critical temperature remains constant in a range of carrier concentrations covering almost three orders of magnitude. The importance of this phenomenon, hereby dubbed a superconducting plateau, is comparable to the celebrated superconducting dome. The dramatic empirical evidence impose severe constraints on any proposal for a superconducting mechanism at low doping. We analyze the experimental results to see what type of theoretical models can be suitable in this regime. We show that the low critical current, absence of diamagnetic screening and the high critical field are all related to the small momentum of the carriers, which is expected at low densities. We quantify the dependency of the critical temperature on density by introducing the "density exponent". We discuss the role of a quantum critical point in the formation of a plateau and comment on the need for more experimental data.
