Strange metals possess highly unconventional electrical properties, such as a linear-in-temperature resistivity^1,2,3,4,5,6, an inverse Hall angle that varies as temperature squared^7,8,9 and a linear-in-field magnetoresistance^10,11,12,13. Identifying the origin of these collective anomalies has proved fundamentally challenging, even in materials such as the hole-doped cuprates that possess a simple bandstructure. The prevailing consensus is that strange metallicity in the cuprates is tied to a quantum critical point at a doping p* inside the superconducting dome^14,15. Here we study the high-field in-plane magnetoresistance of two superconducting cuprate families at doping levels beyond p*. At all dopings, the magnetoresistance exhibits quadrature scaling and becomes linear at high values of the ratio of the field and the temperature, indicating that the strange-metal regime extends well beyond p*. Moreover, the magnitude of the magnetoresistance is found to be much larger than predicted by conventional theory and is insensitive to both impurity scattering and magnetic field orientation. These observations, coupled with analysis of the zero-field and Hall resistivities, suggest that despite having a single band, the cuprate strange-metal region hosts two charge sectors, one containing coherent quasiparticles, the other scale-invariant ‘Planckian’ dissipators.

奇怪的金属具有非常规的电气特性，例如线性温度电阻率^1,2,3,4,5,6，随温度平方^7,8,9变化的反霍尔角和线性场磁阻^10,11,12,13。事实证明，识别这些集体异常的起源具有根本性的挑战性，即使是在具有简单能带结构的空穴掺杂铜酸盐等材料中也是如此。普遍的共识是，铜酸盐中的奇怪金属丰度与超导圆顶^{14,15内掺杂}p *处的量子临界点有关。在这里，我们研究了掺杂水平超过p的两个超导铜酸盐系列的高场面内磁阻*。在所有掺杂中，磁阻都表现出正交缩放，并且在场与温度的比值较高时变为线性，表明奇异金属区域远远超出p *。此外，磁阻的大小被发现比传统理论预测的要大得多，并且对杂质散射和磁场方向都不敏感。这些观察，加上对零场和霍尔电阻率的分析，表明尽管只有一个波段，但铜酸盐奇异金属区域有两个电荷扇区，一个包含相干准粒子，另一个包含尺度不变的“普朗克”耗散器。