de Jong Damaz, Prosko Christian G, Han Lin, Malinowski Filip K, Liu Yu, Kouwenhoven Leo P, Pfaff Wolfgang
QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands.
Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
Phys Rev Lett. 2023 Oct 13;131(15):157001. doi: 10.1103/PhysRevLett.131.157001.
Cooper pair splitters hold utility as a platform for investigating the entanglement of electrons in Cooper pairs, but probing splitters with voltage-biased Ohmic contacts prevents the retention of electrons from split pairs since they can escape to the drain reservoirs. We report the ability to controllably split and retain single Cooper pairs in a multi-quantum-dot device isolated from lead reservoirs, and separately demonstrate a technique for detecting the electrons emerging from a split pair. First, we identify a coherent Cooper pair splitting charge transition using dispersive gate sensing at GHz frequencies. Second, we utilize a double quantum dot as an electron parity sensor to detect parity changes resulting from electrons emerging from a superconducting island.
库珀对分裂器作为研究库珀对中电子纠缠的平台具有实用价值，但使用电压偏置的欧姆接触探测分裂器会导致分裂对中的电子无法保留，因为它们会逃逸到漏极库中。我们报告了在与引线库隔离的多量子点器件中可控地分裂和保留单个库珀对的能力，并分别展示了一种检测分裂对中出现的电子的技术。首先，我们利用GHz频率的色散栅极传感识别相干库珀对分裂电荷跃迁。其次，我们利用双量子点作为电子奇偶性传感器来检测超导岛中出现的电子所导致的奇偶性变化。
