NCTS (South)



PLACE理學教學新大樓物理系3F 36369會議室

FIELDQuantum Information Science

SPEAKER Dr. Jun-Yi Wu(吳俊毅) - 東京大學物理系

TITLEComplementary properties of multiphoton quantum states in linear optics networks

ABSTRACTLinear optics networks (LONs) are linear optical interferometers that interfere and transform optical path modes without an upper limit on the mode number. With single-photon inputs, they are good physical platforms to implement qudit systems that allow arbitrary unitary transformations. One can access quantum coherence in such systems through complementary Pauli measurements in mutually unbiased bases. In multipartite single-photon LONs, the correlations in local complementary Pauli measurements can be further employed in entanglement detection. However, with multiphoton inputs, Boson bunching tangles the photon statistics in LONs, which conceals physical properties that related to quantum coherence behind the complex Boson sampling statistics.
In this talk, we will develop a method for accessing quantum coherence between Fock states in multiphoton LONs by complementary Pauli measurements without dealing with the complexity of the Boson sampling problem. We will then establish a theory for characterization of complementary properties of multiphoton states in LONs using the photon statistics obtained in complementary Pauli measurements. As an important application of the theory, we will demonstrate the detection of entanglement between bipartite multiphoton LONs employing complementary correlations. Our theory opens up access to quantum coherence between Fock states and reveals the physical significance of entanglement between modes in multiphoton LONs.