Structure of Quantum Theory

Quantum state antidistinguishability (also known as quantum state exclusion) concerns the following task: given a quantum state promised to be one of several possible states, find a measurement that conclusively excludes at least one possibility. This talk introduces the concept through key examples and theorems, then turns to its applications in quantum communication and Bell nonlocality. In particular, we show that antidistinguishability is strongly connected to quantum pseudotelepathy, the phenomenon where a Bell game can be won with certainty using quantum resources. Using this connection, we show that quantum pseudotelepathy exists also for non-maximally entangled states, and that every pure entangled state exhibits it in the many-copy scenario.