Abstract: The correlation of a quantum system A to an initially correlated system E generally decreases when A undergoes an evolution separated from E. Here we study the conditions under which the correlation disappears completely, resulting in a decoupling of A from E. Decoupling is a general way to prove many coding theorems in quantum information theory. However existing decoupling constructions use random unitaries which are inefficient to implement. Hence the quest for derandomization.The talk shall describe the decoupling theorem and time permitting, sketch our attempt to derandomize it using a mathematical tool called unitary t-designs.
