Dall'Arno Michele, Brandsen Sarah, Buscemi Francesco, Vedral Vlatko
Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2 117543, Singapore.
California Institute of Technology, 1200 E. California Blvd, Pasadena, California 91125, USA.
Phys Rev Lett. 2017 Jun 23;118(25):250501. doi: 10.1103/PhysRevLett.118.250501. Epub 2017 Jun 22.
We consider the problem of characterizing the set of input-output correlations that can be generated by an arbitrarily given quantum measurement. Our main result is to provide a closed-form, full characterization of such a set for any qubit measurement, and to discuss its geometrical interpretation. As applications, we further specify our results to the cases of real and complex symmetric, informationally complete measurements and mutually unbiased bases of a qubit, in the presence of isotropic noise. Our results provide the optimal device-independent tests of quantum measurements.
我们考虑刻画由任意给定量子测量所产生的输入-输出关联集的问题。我们的主要结果是针对任意量子比特测量，给出这样一个集合的封闭形式的完整刻画，并讨论其几何解释。作为应用，在存在各向同性噪声的情况下，我们将结果进一步细化到实对称、复对称、信息完备测量以及量子比特的相互无偏基的情形。我们的结果提供了量子测量的最优与设备无关的检验。
