Linear-in temperature resistivity from an isotropic Planckian scattering rate
Linear-in temperature resistivity from an isotropic Planckian scattering rate
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DOI：
10.1038/s41586-021-03697-8
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发表时间：
2021-07-29
期刊：
影响因子：
64.8
通讯作者：
Ramshaw, B. J.
中科院分区：
文献类型：
--
作者：
Grissonnanche, Gael;Fang, Yawen;Ramshaw, B. J.
当温度降至零 (1-3) 时，各种“奇怪金属”的电阻率会随温度线性降低，而传统金属的电阻率随温度呈二次方降低。这种线性温度电阻率归因于载流子以 h/tau = alpha k(B)T 给出的速率散射，其中 alpha 是单位常数，h 是普朗克常数，k(B) 是玻尔兹曼常数。在多种材料中都观察到了散射率与温度之间的这种简单关系，这表明了散射的基本上限——“普朗克极限”(4,5)——但人们对这一极限的根本起源知之甚少。在此，我们报告了 La1.6-xNd0.4SrxCuO4（一种空穴掺杂铜酸盐）的角度相关磁阻测量结果，该材料在最低测量温度下显示出线性温度电阻率 (6)。角度相关的磁阻显示了一个明确的费米表面，该表面与角度分辨光电子能谱测量定量一致(7)，并揭示了在普朗克极限处饱和的线性温度散射率，即 alpha = 1.2 +/- 0.4。值得注意的是，我们发现这种普朗克散射率是各向同性的，也就是说，它与方向无关，这与“热点”模型的预期相反（8,9）。我们的研究结果表明，奇异金属中的线性温度电阻率源于达到普朗克极限的动量无关非弹性散射率。对空穴掺杂铜酸盐的奇异金属相进行的角度相关磁阻测量显示出明确的费米表面和在普朗克极限处饱和的各向同性线性温度散射率。
A variety of 'strange metals' exhibit resistivity that decreases linearly with temperature as the temperature decreases to zero(1-3), in contrast to conventional metals where resistivity decreases quadratically with temperature. This linear-in-temperature resistivity has been attributed to charge carriers scattering at a rate given by h/tau = alpha k(B)T, where alpha is a constant of order unity, h is the Planck constant and k(B) is the Boltzmann constant. This simple relationship between the scattering rate and temperature is observed across a wide variety of materials, suggesting a fundamental upper limit on scattering-the 'Planckian limit'(4,5)-but little is known about the underlying origins of this limit. Here we report a measurement of the angle-dependent magnetoresistance of La1.6-xNd0.4SrxCuO4-a hole-doped cuprate that shows linear-in-temperature resistivity down to the lowest measured temperatures(6). The angle-dependent magnetoresistance shows a well defined Fermi surface that agrees quantitatively with angle-resolved photoemission spectroscopy measurements(7) and reveals a linear-in-temperature scattering rate that saturates at the Planckian limit, namely alpha = 1.2 +/- 0.4. Remarkably, we find that this Planckian scattering rate is isotropic, that is, it is independent of direction, in contrast to expectations from 'hotspot' models(8,9). Our findings suggest that linear-in-temperature resistivity in strange metals emerges from a momentum-independent inelastic scattering rate that reaches the Planckian limit.Angle-dependent magnetoresistance measurements of a strange-metal phase of a hole-doped cuprate show a well defined Fermi surface and an isotropic linear-in-temperature scattering rate that saturates at the Planckian limit.