论文标题
各向同性普兰克散射率的线性温度电阻率
Linear-in temperature resistivity from an isotropic Planckian scattering rate
论文作者
论文摘要
各种“奇怪的金属”具有电阻率，与温度为$ t \ rightarrow 0 $线性降低，与传统的金属相比，电阻率降低为$ t^2 $。该$ t $ - 线性电阻率已归因于载体散射的速度为$ \ hbar/τ=αk_ {\ rm b} t $，其中$α$是订单统一的常数。在各种材料上观察到散射速率和温度之间的这种简单关系，这表明散射的基本上限 - “ Planckian极限” - 但对此极限的基本起源知之甚少。在这里，我们报告了ND-LSCO的角度依赖性磁倍率（ADMR）的测量---掺杂孔的库酸盐，显示出$ t $ - 线性电阻率，降至最低测量的温度。 ADR揭示了一个定义明确的费米表面，该表面与角度分辨的光发射光谱（ARPES）测量数量同意，并揭示了$ t $ - 线性散射速率，使Planckian限制饱和，即$ $ $α= 1.2 \ pm 0.4 $。值得注意的是，我们发现，与“热点”模型的期望相反，这种普朗克散射速率是各向同性的，即它独立于方向。我们的发现表明，奇怪金属中的$ t $线性电阻率是由于动量独立的非弹性散射率而出现的，该弹性散射速率达到了普兰克限制。
A variety of "strange metals" exhibit resistivity that decreases linearly with temperature as $T\rightarrow 0$, in contrast with conventional metals where resistivity decreases as $T^2$. This $T$-linear resistivity has been attributed to charge carriers scattering at a rate given by $\hbar/τ=αk_{\rm B} T$, where $α$ is a constant of order unity. 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"---but little is known about the underlying origins of this limit. Here we report a measurement of the angle-dependent magnetoresistance (ADMR) of Nd-LSCO---a hole-doped cuprate that displays $T$-linear resistivity down to the lowest measured temperatures. The ADMR unveils a well-defined Fermi surface that agrees quantitatively with angle-resolved photoemission spectroscopy (ARPES) measurements and reveals a $T$-linear scattering rate that saturates the Planckian limit, namely $α= 1.2 \pm 0.4$. Remarkably, we find that this Planckian scattering rate is isotropic, i.e. it is independent of direction, in contrast with expectations from "hot-spot" models. Our findings suggest that $T$-linear resistivity in strange metals emerges from a momentum-independent inelastic scattering rate that reaches the Planckian limit.
