arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1212.3545cond-mat.mes-hall
收藏

电磁驱动相互作用量子系统中的零频噪声

Zero-frequency noise in adiabatically driven, interacting quantum systems

Roman-Pascal Riwar, Janine Splettstoesser, Jürgen König

摘要:

研究了弱耦合量子点中绝热电荷泵的电流-电流关联。为了计算零频率噪声的时间依赖性驱动的系统,可能在存在一个额外的直流偏置,我们在一个实时的图解方法内执行一个微扰膨胀的隧道耦合到水库的领先和下一个领先的顺序。我们应用这种形式主义来研究零频率噪声的绝热校正,即,在单级量子点电荷泵的情况下的泵浦噪声。如果没有固定的偏压,绝热修正显示库仑相互作用引起的偏差的波动耗散定理。此外,我们表明,绝热修正的Fano因子携带的耦合不对称性的信息,是独立的泵浦参数的选择。当包括一个与时间相关的有限偏压时,我们发现,即使有零的相干泵浦电荷,也会有泵浦噪声。泵浦噪声还指示偏置感应电流和泵浦电流的相应方向。

英文摘要:

We investigate current-current correlations of adiabatic charge pumping through interacting quantum dots weakly coupled to reservoirs. To calculate the zero-frequency noise for a time-dependently driven system, possibly in the presence of an additional dc bias, we perform within a real-time diagrammatic approach a perturbative expansion in the tunnel coupling to the reservoirs in leading and next-to-leading order. We apply this formalism to study the adiabatic correction to the zero-frequency noise, i.e., the pumping noise, in the case of a single-level quantum dot charge pump. If no stationary bias is applied, the adiabatic correction shows Coulomb-interaction-induced deviations from the fluctuation-dissipation theorem. Furthermore, we show that the adiabatic correction to the Fano factor carries information about the coupling asymmetry and is independent of the choice of the pumping parameters. When including a time-dependent finite bias, we find that there can be pumping noise even if there is zero adiabatically pumped charge. The pumping noise also indicates the respective direction of the bias-induced current and the pumping 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。

↑