High-Efficiency Cooper-Pair Splitter in Quantum Anomalous Hall Insulator Proximity-Coupled with Superconductor.
High-Efficiency Cooper-Pair Splitter in Quantum Anomalous Hall Insulator Proximity-Coupled with Superconductor.
复制标题
与超导体邻近耦合的量子反常霍尔绝缘体中的高效库珀对分路器
DOI：
10.1038/srep14892
复制
发表时间：
2015-10-09
影响因子：
4.6
通讯作者：
Qiao Z
中科院分区：
文献类型：
--
作者：
Zhang YT;Deng X;Sun QF;Qiao Z
两个量子比特之间的量子纠缠对于量子通信的应用至关重要。在实验上实现了光子的纠缠之后，人们开始致力于在固态系统中利用纠缠电子。在这里，我们提出了一个库珀对分裂器，它可以产生空间分离，但纠缠的电子，在量子反常霍尔绝缘体邻近耦合的超导体。在与超导体耦合后，量子反常霍尔绝缘体的手征边缘态仍然可以存活，使得背散射成为不可能。因此，局部Andreev反射变为消失，而交叉Andreev反射在散射过程中变为主导。这表明我们的器件可以作为一个非常高效的库珀对分裂器。此外，由于手性特性，我们的库珀对分裂器是强大的，对混乱，可以在很宽的系统参数范围内工作。特别地，即使系统长度超过超导相干长度，它仍然可以起作用。
The quantum entanglement between two qubits is crucial for applications in the quantum communication. After the entanglement of photons was experimentally realized, much effort has been taken to exploit the entangled electrons in solid-state systems. Here, we propose a Cooper-pair splitter, which can generate spatially-separated but entangled electrons, in a quantum anomalous Hall insulator proximity-coupled with a superconductor. After coupling with a superconductor, the chiral edge states of the quantum anomalous Hall insulator can still survive, making the backscattering impossible. Thus, the local Andreev reflection becomes vanishing, while the crossed Andreev reflection becomes dominant in the scattering process. This indicates that our device can serve as an extremely high-efficiency Cooper-pair splitter. Furthermore, because of the chiral characteristic, our Cooper-pair splitter is robust against disorders and can work in a wide range of system parameters. Particularly, it can still function even if the system length exceeds the superconducting coherence length.