Attractive and driven interactions in quantum dots: Mechanisms for geometric pumping
Attractive and driven interactions in quantum dots: Mechanisms for geometric pumping
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量子点中有吸引力和驱动的相互作用：几何泵浦机制
DOI：
10.1103/physrevb.98.085307
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发表时间：
2018
影响因子：
3.7
通讯作者：
M. Wegewijs
中科院分区：
文献类型：
--
作者：
B. Placke;T. Plücker;J. Splettstoesser;M. Wegewijs;M. Wegewijs
我们分析了通过量子点的电子-电子相互作用，是静态可调的排斥和吸引力的制度，甚至动态驱动的时间相关的运输。最近的实验结果[A]。Hamo，Nature（伦敦）535，395（2016）NATUAS 0028 -083610.1038/nature 18639]中的静态双量子点中的这种系统，我们计算了弱隧穿、高温和慢驱动极限下的电荷的几何泵浦。我们分析了所有可能的泵浦实验或“驱动协议”的响应，每个定义通过选择一对驱动参数（栅极电压，偏置电压，隧道耦合，电子-电子相互作用）。我们表明，不同的实验，这样的响应可以由一个共同的，基本的泵送机制，其特征在于由一组有效的参数。后者是实验驱动参数和其他静态参数的非平凡组合。如果两个不同的泵浦实验导致有效参数的相同调制，即，基本的机制是一样的，那么他们的反应也是一样的。有趣的是，对于静态吸引相互作用，我们发现一个非零的泵浦响应，尽管有吸引力的库仑阻塞，阻碍静态运输。此外，我们确定了一个独特的泵送响应，其基本机制依赖于相互作用的驱动参数之一：它不能获得与其他组的驱动参数。最后，虽然一个单点模型与轨道赝自旋描述了上述实验装置的大部分物理，它是至关重要的帐户额外的（真实的）自旋简并的双点和相关的电子空穴对称性破缺。这是必要的，因为泵浦响应比直流传输测量更敏感，并通过明显的定性效应检测这种差异。
We analyze time-dependent transport through a quantum dot with electron-electron interaction that is statically tunable to both repulsive and attractive regimes, or even dynamically driven. Motivated by the recent experimental realization [A. Hamo, Nature (London) 535, 395 (2016)NATUAS0028-083610.1038/nature18639] of such a system in a static double quantum dot we compute the geometric pumping of charge in the limit of weak tunneling, high temperature, and slow driving. We analyze the responses for all possible pumping experiments or "driving protocols", each defined by choosing a pair of driving parameters (gate voltage, bias voltage, tunnel coupling, electron-electron interaction). We show that such responses for different experiments can be governed by a common, underlying pumping mechanism, which is characterized by a set of effective parameters. The latter are nontrivial combinations of the experimentally driven parameters and other static parameters. If two different pumping experiments result in the same modulation of the effective parameters, i.e., the underlying mechanism is the same, then their responses will also be the same. Interestingly, for static attractive interaction we find a nonzero pumping response despite the attractive Coulomb blockade that hinders stationary transport. Furthermore, we identify a unique pumping response whose underlying mechanism relies on the interaction to be one of the driving parameters: it cannot be obtained with other sets of driving parameters. Finally, although a single-dot model with orbital pseudospin describes most of the physics of the mentioned experimental setup, it is crucial to account for the additional (real-)spin degeneracy of the double dot and the associated electron-hole symmetry breaking. This is necessary because the pumping response is more sensitive than dc transport measurements and detects this difference through pronounced qualitative effects.
相互作用开放系统中的费米子宇称对偶性和能量弛豫
影响因子：
3.7
作者：
Schulenborg;Saptsov;Splettstoesser;Wegewijs
通讯作者：
Wegewijs