压力过掺杂铜氧化物中190 K下存在超导性的证据
Evidence for superconductivity at 190 K in a pressure-overdoped cuprate
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中文总结 AI 辅助
本研究针对铜氧化物超导体临界温度的压力调控问题，通过多种技术测试Bi-2223在60 GPa压力下的迈斯纳效应，发现其临界温度可达190 K，为高空穴掺杂下的第二超导相理论提供了实验证据。
中文摘要 AI 辅助
铜氧化物超导体的临界温度（$T_c$）可通过压力调控，这一点已得到充分证实。例如，加压可使空穴掺杂与化学掺杂解耦，从而获得远超常压条件下所能实现的过掺杂样品。本研究采用多种技术，在不同压缩环境下，探究了$\boldsymbol{\rm Pb_{0.4}Bi_{1.6}Sr_2Ca_2Cu_3O_{10+δ}}$（Bi-2223）在最高60 GPa压力下，$T_c$处迈斯纳效应的起始点随压力的变化规律。在准静水压条件下压缩的样品，在25 GPa以下表现出独特的$T_c$非单调压力依赖性，与此前的报道一致。随着压力进一步升高，$T_c$持续攀升，在60 GPa时达到190 K。该研究得到的临界温度证据超过了目前已报道的铜氧化物在常压和高压下的临界温度，其结果可通过已提出的高空穴掺杂下的第二超导相来解释。
英文摘要
It is well established that the critical temperature ($T_c$) of cuprate superconductors can be tuned by pressure. For example, compression decouples the hole doping from chemical doping allowing for overdoped samples far beyond what is possible at ambient pressure. In this work, multiple techniques are used to probe the onset of the Meissner effect at $T_c$ as a function of pressure in $\mathrm{Pb_{0.4}Bi_{1.6}Sr_2Ca_2Cu_3O_{10+δ}}$ (Bi-2223) to 60 GPa in different compression environments. Samples compressed under quasihydrostatic conditions exhibit a distinctive non-monotonic pressure dependence of $T_c$ below 25 GPa, in agreement with previous reports. With further increase in pressure $T_c$ climbs continuously to 190 K at 60 GPa. Evidence for critical temperatures exceeding those reported to date for cuprates at ambient and high pressures, the results may be understood in terms of the proposed second superconducting regime at high hole doping.
