Measuring non-Markovianity of processes with controllable system-environment interaction

Abstract

Non-Markovian processes have recently become a central topic in the study of\nopen quantum systems. We realize experimentally non-Markovian decoherence\nprocesses of single photons by combining time delay and evolution in a\npolarization-maintaining optical fiber. The experiment allows the\nidentification of the process with strongest memory effects as well as the\ndetermination of a recently proposed measure for the degree of quantum\nnon-Markovianity based on the exchange of information between the open system\nand its environment. Our results show that an experimental quantification of\nmemory in quantum processes is indeed feasible which could be useful in the\ndevelopment of quantum memory and communication devices.\n