Finite vs. unlimited LOCC
Previous problem: Bell inequalities and operator algebras
Is there an advantage in using unlimited rather than finite LOCC?
An LOCC (local operation and classical communication) protocol usually consists of discrete steps, where in each step, all parties apply some local quantum operation and occasionally obtain a measurement result. The measurement results are shared between all parties.
A protocol can be unlimited in at least three ways: the local parties may use continuous ancilla systems, the measurement results might be continuous (e.g. a real number) and the number of protocol steps could be infinite (e.g. weak measurements and post-selection).
So far, this problem has only been considered for the discrimination of orthogonal states. Results: