title: Experimental detection of quantum coherent evolution through the violation of Leggett-Garg-type inequalities.
abstract: We discuss the use of inequalities of the Leggett-Garg type (LGtI) to witness quantum coherence and present the first experimental violation of this type of inequalities using a light-matter interfaced system. By separately benchmarking the Markovian character of the evolution and the translational invariance of the conditional probabilities, the observed violation of a LGtI is attributed to the quantum coherent character of the process. These results provide a general method to benchmark "quantumness" when the absence of memory effects can be independently certified and confirm the persistence of quantum coherent features within systems of increasing complexity.
authors.affiliation: Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Zong-Quan
authors.initials: ZQ
authors.lastname: Zhou
authors.affiliation: Institut für Theoretische Physik, Albert-Einstein-Allee 11, Universität Ulm, D-89069 Ulm, Germany.
authors.forename: Susana F
authors.initials: SF
authors.lastname: Huelga
authors.affiliation: Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Chuan-Feng
authors.initials: CF
authors.lastname: Li
authors.affiliation: Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Guang-Can
authors.initials: GC
authors.lastname: Guo