Prof. Yueh-Nan Chen (Dep. of Physics, NCKU, and Center Scientist of NCTS) and his student collaborate with Prof. Yeong-Cherng Liang (professor of NCKU, TG6) published their recent works in Phys. Rev. Lett. on the topic of Device-independent quantification of quantum steerability. They introduce the concept of assemblage moment matrices and demonstrate how it can be used for quantum states and measurements characterization in a device-independent manner, i.e., without invoking any assumption about the measurement nor the preparation device. In addition, by proving a quantitative relationship between steering robustness and the recently introduced incompatibility robustness, their approach also allows for a device-independent quantification of the incompatibility between various measurements performed in a Bell-type experiment. Explicit examples where such bounds provide a kind of self-testing of the performed measurements are provided.
Figure Caption: Schematic diagram showing how our assemblage moment matrices (AMM) approach allows for a black-box estimation [i.e., using only P(a,b|x,y)] of various quantities of interest, such as steering robustness via Eq. (5), steerable weight via Eq. (B6) [72], and incompatibility robustness of measurements via Eq. (8). See the manuscript for more details.
Reference
[1] Natural framework for device-independent quantification of quantum steerability, measurement incompatibility, and self-testing,
Shin-Liang Chen, Costantino Budroni, Yeong-Cherng Liang, and Yueh-Nan Chen, Phys. Rev. Lett. 116, 240401(2016).
