Speaker
Description
Given a quantum state, how can we tell how "quantum" it is? That is, can we use that quantum state to do kick-start an interesting protocol like quantum teleportation, or is it really just a classical state in disguise? Quantum coherence tries to answer this question by quantifying the amount of superposition present in a quantum state. We develop some new easy-to-compute methods of determining how much coherence is present in a quantum state, and we establish a connection with the seemingly unrelated problem of antidistinguishability: if we are given a pure quantum state from some fixed set, is there a measurement that determines at least one state that we were not given? As an application of our results, we derive a correct version of a recently-disproved conjecture about antidistinguishability of quantum states.
