Scalable on-chip quantum state tomography
Scalable on-chip quantum state tomography
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DOI：
10.1038/s41534-018-0063-5
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发表时间：
2017-04
影响因子：
7.6
通讯作者：
James G. Titchener;M. Gräfe;R. Heilmann;A. Solntsev;A. Szameit;A. Sukhorukov
中科院分区：
文献类型：
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作者：
James G. Titchener;M. Gräfe;R. Heilmann;A. Solntsev;A. Szameit;A. Sukhorukov
量子信息系统正走在一条大大超过任何经典设备复杂性的道路上。量子设备中纠缠量子比特的数量正在迅速增加，并且完全描述这些系统所需的信息与量子比特数量呈指数关系。这种缩放是量子系统的关键优势，但它也带来了严峻的挑战。为了表征这样的系统，通常需要指数级长的不同测量序列，对于大量的量子比特来说，这对资源的要求很高。在这里，我们提出并证明了一种新的和可扩展的方法来表征量子系统的基础上扩展的多光子状态到更大的维度。我们确定，这种新的测量技术的复杂性只与量子位的数量成线性关系，同时提供了一个完整的数据集，而不需要重新配置。我们实验证明了一个集成的光子芯片能够测量两个和三个光子量子态的统计重建保真度为99.71%。
Quantum information systems are on a path to vastly exceed the complexity of any classical device. The number of entangled qubits in quantum devices is rapidly increasing, and the information required to fully describe these systems scales exponentially with qubit number. This scaling is the key benefit of quantum systems, however it also presents a severe challenge. To characterize such systems typically requires an exponentially long sequence of different measurements, becoming highly resource demanding for large numbers of qubits. Here we propose and demonstrate a novel and scalable method for characterizing quantum systems based on expanding a multi-photon state to larger dimensionality. We establish that the complexity of this new measurement technique only scales linearly with the number of qubits, while providing a tomographically complete set of data without a need for reconfigurability. We experimentally demonstrate an integrated photonic chip capable of measuring two- and three-photon quantum states with statistical reconstruction fidelity of 99.71%.