Restoring the strange metal phase via suppression of charge density waves in an underdoped cuprate superconductor

[This repository contains the raw data for the manuscript "<strong>Restoring the strange metal phase via suppression of charge density waves in an underdoped cuprate superconductor</strong>" (arXiv:2009.08398)] The normal state of cuprates is dominated by the “strange metal” phase that, near optimal doping, shows a linear temperature dependence of the resistivity persisting down to the lowest <em>T</em>, when superconductivity is suppressed. For underdoped cuprates this behavior is lost below the pseudogap temperature <em>T</em>*, where Charge Density Waves (CDW) together with other intertwined local orders characterize the ground state. Here we show that the <em>T</em>-linear resistivity of highly strained, ultrathin and underdoped YBa₂Cu₃O_7-δ films is restored when the CDW amplitude, detected by Resonant Inelastic X-ray scattering, is suppressed. This observation points towards an intimate connection between the onset of CDW and the departure from <em>T</em>-linear resistivity in underdoped cuprates, a link that was missing until now. It also illustrates the potentiality of strain control to manipulate the ground state of quantum materials.本仓库收录了论文《通过抑制欠掺杂铜基超导体中的电荷密度波以恢复奇异金属相》（arXiv:2009.08398）的原始实验数据。铜基超导体的正常态以奇异金属（strange metal）相为主导：在最佳掺杂附近，当超导性被抑制时，电阻率的线性温度依赖关系可延续至最低温度。对于欠掺杂铜基超导体，这一行为会在赝能隙温度T*以下消失；此时电荷密度波（charge density waves, CDW）与其他相互交织的局域序共同构成了基态的典型特征。本文结果表明，经共振非弹性X射线散射（Resonant Inelastic X-ray scattering）探测到的电荷密度波振幅被抑制后，高应变、超薄欠掺杂钇钡铜氧（YBa₂Cu₃O₇₋δ）薄膜的T线性电阻率得以恢复。该观测结果暗示，欠掺杂铜基超导体中电荷密度波的出现与偏离T线性电阻率行为之间存在紧密关联——这一关联此前尚未被揭示。同时，本研究也展示了应变调控在操控量子材料基态方面的应用潜力。