Quantum correlations for anonymous metrology

Abstract

We introduce the task of anonymous metrology, in which a physical parameter of an object may be determined without revealing the object's location. Alice and Bob share a correlated quantum state, with which one of them probes the object. Upon receipt of the quantum state, Charlie is then able to estimate the parameter without knowing who possesses the object. We show that quantum correlations are resources for this task when Alice and Bob do not trust the devices in their labs. The anonymous metrology protocol moreover distinguishes different kinds of quantum correlations according to the level of desired security: discord is needed when the source of states is trustworthy, otherwise entanglement is necessary.

Quantum Delocalized Interactions

“…This stands in stark contrast to our classical intuition that interactions happen at unique places, we just might not know where. This nonclassical phenomenon has in fact been instrumental in enabling certain quantum protocols [28,29].…”

“…Information encoded using nonlocally superposed quantum states is recorded via local interactions while disturbing the superposition less than would be classically possible. This phenomenon has interesting foundational implications regarding events not requiring unique locations and has also been a key component for certain quantum protocols [28,29]. In order to systematically study this quantum effect, we introduced and investigated quantum games for which nonclassical performance demonstrates delocalized interactions.…”

Probabilistic and Approximate Masking of Quantum Information

“…Moreover, when one allows for some trusted randomness in the protocol, the set of maskable states grows [25,26], even to a point where universal masking becomes possible. These non-trivial features of the no-masking theorem has generated significant interest in the recent years [27][28][29][30][31][32].…”