论文标题
未界的无界随机性来自未表征的来源
Unbounded randomness from uncharacterized sources
论文作者
论文摘要
随机性是量子力学的主要特征，也是经典技术和量子技术的宝贵资源。通常，在与设备无关的和半设备无关的场景中，随机性是使用投影测量值认证的，并且经过认证的随机性数量受测量量子系统的尺寸界定。在这项工作中，我们基于正运算符的有价值测量值（POVM）提出了一个新的与源设备设备的协议，该协议可以任意增加任何固定尺寸的认证位数。考虑到量子侧信息，仅使用POVM结构和实验期望值来得出量子条件最小内侧面的紧密下限。对于Bloch球体上的对称POVM测量，我们得出了封闭形式的分析界限。最后，我们通过实验性地通过紧凑而简单的光子设置来证明我们的方法，该设置采用了极化定型的Qubits和POVM多达6个结果。
Randomness is a central feature of quantum mechanics and an invaluable resource for both classical and quantum technologies. Commonly, in Device-Independent and Semi-Device-Independent scenarios, randomness is certified using projective measurements and the amount of certified randomness is bounded by the dimension of the measured quantum system. In this work, we propose a new Source-Device-Independent protocol, based on Positive Operator Valued Measurement (POVM), which can arbitrarily increase the number of certified bits for any fixed dimension. A tight lower-bound on the quantum conditional min-entropy is derived using only the POVM structure and the experimental expectation values, taking into account the quantum side-information. For symmetrical POVM measurements on the Bloch sphere we have derived closed-form analytical bounds. Finally, we experimentally demonstrate our method with a compact and simple photonic setup that employs polarization-encoded qubits and POVM up to 6 outcomes.
