المعدن الخفي داخل الموصلات الفائقة سريع

الملخص الأصلي

كما كتبه المؤلفون، بالإنجليزية arXiv:2604.10133

Nuclear relaxation is a very robust probe of electronic excitations in superconducting materials, above and below the critical temperature of superconductivity, $$T_\mathrm{c}$$. Here, a phenomenology of it in cuprate superconductors is established based on essentially all cuprate data available in the literature from the CuO$$_2$$ plane. A universal 'hidden metal' with $$1/T_1 T = const$$ reigns below the pseudogap line, and, similar to usual superconducting metals, all cuprates condense at $$T_\mathrm{c}$$ out of this metal and relaxation ceases rapidly. There is no Hebel-Slichter peak. Above the hidden metal, a renormalized two-component metal is found. Therefore, the hidden metal is identified as the pseudogap matter, which has other important properties. It predominantly lacks a uniform response, unlike the normal metal above $$T^*$$, and it does not significantly relax planar O. However, for planar Cu it exhibits a special relaxation anisotropy. With the field in the plane, it causes a relaxation rate that is very similar for all cuprates, $$1/{^{63}T}_{1\perp}T\approx 25/$$Ks, while with the field parallel to the $$c$$-axis, $$1/{^{63}T}_{1\parallel}T$$, the proportional rate (in the pseudogap range) changes as a function of doping and material. This relaxation anisotropy is strictly correlated with the maximum critical temperature, $$T_\mathrm{c,max}$$, of all cuprates. It is stipulated that two partially independent spin components are needed to understand this behavior. The new phenomenology will be discussed and should give a better foundation for the understanding of the cuprates