Entanglement characterization is a preliminary step in the implementation of many quantum information processing tasks. In this talk, I will describe some recent progress on the possibility to characterize entanglement in a device-independent manner, i.e., directly from the observed measurement statistics without relying on any assumption about the systems observed or of the measurements performed. In particular, I will describe a technique that allows for the characterization of correlations derived from quantum states having additional property, such as positive partial transposition. This, in turn, permits the quantification of entanglement as well as the certification of many-body entanglement (i.e., entanglement depth) in a device-independent manner. Specifically, from the observed correlations or the amount of violation of a given Bell inequality, we can provide non-trivial lower bounds on the amount of (genuine) negativity present in the measured quantum state and/or the extent to which it is many-body entangled. The bounds on negativity, in turn, provide further information about the dimension of the underlying Hilbert space and/or the type of entanglement responsible for the observed correlations.
Currently, Prof. Liang is an assistant Professor in the Department of Physics at National Cheng Kung University, Taiwan. He did his Bachelor’s and Master’s degree at the National University of Singapore. He did his post-doc in various places, including University of Sydney, University of Geneva, and ETH Zurich. Prof. Liang’s research mainly focuses on Quantum entanglement, quantum nonlocality and device-independent characterizations.