论文标题
西奈模型在DNA解动中的实验测试
Experimental test of Sinai's model in DNA unzipping
论文作者
论文摘要
无序系统中相关函数和关键指数的实验测量是测试重生组（RG）预测的关键。我们用光学镊子机械解开单个DNA发夹，这是对粒子在一维随机力场（称为西奈模型）中扩散运动的实验实现。我们测量UNIPPICT力量$ f_w $作为陷阱位置$ W $平衡的函数，并计算力强度相关器$Δ_M（W）$，其幅度和相关长度，从而找到与理论预测的一致性。我们研究了通用缩放属性，因为有效的陷阱刚度$ m^2 $在解压缩时会降低。基本对位置在Unzipping交界$ u $ scales上的位置的波动为$ u \ sim m^{ - ζ} $，具有粗糙度指数$ζ= 1.34 \ pm0.06 $，与分析预测$ζ= \ζ= \ frac {4} {3} $一致。我们的研究提供了对无序弹性系统在平衡中的功能性RG方法的单分子测试。
The experimental measurement of correlation functions and critical exponents in disordered systems is key to testing renormalization group (RG) predictions. We mechanically unzip single DNA hairpins with optical tweezers, an experimental realization of the diffusive motion of a particle in a one-dimensional random force field, known as the Sinai model. We measure the unzipping forces $F_w$ as a function of the trap position $w$ in equilibrium and calculate the force-force correlator $Δ_m(w)$, its amplitude, and correlation length, finding agreement with theoretical predictions. We study the universal scaling properties since the effective trap stiffness $m^2$ decreases upon unzipping. Fluctuations of the position of the base pair at the unzipping junction $u$ scales as $u \sim m^{-ζ}$, with a roughness exponent $ ζ=1.34\pm0.06$, in agreement with the analytical prediction $ζ= \frac{4}{3}$. Our study provides a single-molecule test of the functional RG approach for disordered elastic systems in equilibrium.
