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arXiv 0910.0119cond-mat.str-elcond-mat.mes-hall
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弛豫与退相干:各向异性Kondo模型在有限偏压和磁场下的自旋和电流动力学

Relaxation vs decoherence: Spin and current dynamics in the anisotropic Kondo model at finite bias and magnetic field

Mikhail Pletyukhov, Dirk Schuricht, Herbert Schoeller

摘要:

利用非平衡重整化群方法研究了各向异性Kondo模型(包括反铁磁和铁磁)在有限磁场$h_0$和偏压$V$作用下自旋和电流的实时演化.我们推导出解析表达式的所有时间在弱耦合制度$\max\{V,h_0,1/t\}\gg T_c$($T_c=$强耦合规模)。我们发现所有的观测量都随自旋弛豫和退相干速率$Γ_{1/2}$衰减。各种$V$依赖的对数,振荡和幂律的贡献进行了预测。对数项的低能截止一般由输运衰减率的差异来确定。对于小的时间$t\ll \max\{V,h_0\}^{-1}$,我们得到的自旋和电流的普遍动力学。

英文摘要:

Using a nonequilibrium renormalization group method we study the real-time evolution of spin and current in the anisotropic Kondo model (both antiferromagnetic and ferromagnetic) at finite magnetic field $h_0$ and bias voltage $V$. We derive analytic expressions for all times in the weak-coupling regime $\max\{V,h_0,1/t\}\gg T_c$ ($T_c=$ strong coupling scale). We find that all observables decay both with the spin relaxation and decoherence rates $Γ_{1/2}$. Various $V$-dependent logarithmic, oscillatory, and power-law contributions are predicted. The low-energy cutoff of logarithmic terms is generically identified by the difference of transport decay rates. For small times $t\ll \max\{V,h_0\}^{-1}$, we obtain universal dynamics for spin and current.

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。

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