arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1107.4265cond-mat.mes-hall
收藏

交流理论近藤机制下量子点的自旋流噪声和自旋电导I:平衡态

Theory of a.c. spin current noise and spin conductance through a quantum dot in the Kondo regime I: The equilibrium case

C. P. Moca, I. Weymann, G. Zarand

摘要:

我们分析了在局域矩体系中量子点的平衡态自旋流噪声和自旋电导。自旋电流关联的行为明显不同于电荷关联。平衡自旋关联在没有外场的情况下由两个普适标度函数表征:其中一个与电荷关联有关,而另一个描述交叉自旋关联。我们使用微扰和非微扰方法相结合的特点,这些功能。我们发现,在低温下,自旋互相关被抑制在低于近藤标度,$T_K$的频率,并发现在近藤能量,$ω\sim T_K$的动态自旋积累共振。在更高的温度下,$T>T_K$,令人惊讶的低频异常相关的整体自旋守恒出现在自旋噪声和自旋电导,和Korringa率被证明发挥了杰出的作用。瞬态自旋电流响应也显示出普遍和奇异的性质。

英文摘要:

We analyze the equilibrium frequency-dependent spin current noise and spin conductance through a quantum dot in the local moment regime. Spin current correlations behave markedly differently from charge correlations. Equilibrium spin correlations are characterized by two universal scaling functions in the absence of an external field: one of them is related to charge correlations, while the other one describes cross-spin correlations. We characterize these functions using a combination of perturbative and non-perturbative methods. We find that at low temperatures spin cross-correlations are suppressed at frequencies below the Kondo scale, $T_K$, and a dynamical spin accumulation resonance is found at the Kondo energy, $ω\sim T_K$. At higher temperatures, $T>T_K$, surprising low-frequency anomalies related to overall spin conservation appear in the spin noise and spin conductance, and the Korringa rate is shown to play a distinguished role. The transient spin current response also displays universal and singular properties.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑