Quantum objects, sometimes called quantons, often display a characteristic feature referred to as wave-particle duality (WPD). Lately, this and other quantum traits have been subjected to intensive research, mainly motivated by the development of quantum information science. As a consequence, the scopes of some concepts have been extended, and it has been realized that they are not in the exclusive domain of quantum physics. This is particularly clear in optics, where qubits may show up as Jones vectors and WPD has its counterpart as wave-ray duality. WPD was originally addressed by focusing on a single qubit, which was afterwards supplemented with a second one playing the role of a path-marker in an interferometer setup. Fringe contrast, a sign of wave-like behavior, was proved to be diminished in connection with the effectiveness of the marker, the inducer of particle-like behavior. Going from bipartite to tripartite states is a natural and necessary step towards better understanding of WPD. This step is what we have accomplished in this work. We report some constraints ruling WPD for tripartite systems, as well as their experimental display with single photons.Quantum objects, sometimes called quantons, often display a characteristic feature referred to as wave-particle duality (WPD). Lately, this and other quantum traits have been subjected to intensive research, mainly motivated by the development of quantum information science. As a consequence, the scopes of some concepts have been extended, and it has been realized that they are not in the exclusive domain of quantum physics. This is particularly clear in optics, where qubits may show up as Jones vectors and WPD has its counterpart as wave-ray duality. WPD was originally addressed by focusing on a single qubit, which was afterwards supplemented with a second one playing the role of a path-marker in an interferometer setup. Fringe contrast, a sign of wave-like behavior, was proved to be diminished in connection with the effectiveness of the marker, the inducer of particle-like behavior. Going from bipartite to tripartite states is a natural and necessary step towards better understanding of WPD. This step is what we have accomplished in this work. We report some constraints ruling WPD for tripartite systems, as well as their experimental display with single photons.

Journal of the Optical Society of America AJan 23, 20234 citations

Entropic framework for wave-particle duality in multipath interferometers

Patrick J. Coles

An interferometer---no matter how clever the design---cannot reveal both the wave and the particle behavior of a quantum system. This fundamental idea has been captured by inequalities, so-called wave-particle duality relations (WPDRs), that upper bound the sum of the fringe visibility (wave behavior) and path distinguishability (particle behavior). Another fundamental idea is Heisenberg's uncertainty principle, stating that some pairs of observables cannot be known simultaneously. Recent work has unified these two principles for two-path interferometers. Here we extend this unification to $n$ -path interferometers, showing that WPDRs correspond to a modern formulation of the uncertainty principle stated in terms of entropies. Furthermore, our unification provides a framework for solving an outstanding problem of how to formulate universally valid WPDRs for interferometers with more than two paths, and we employ this framework to derive some novel WPDRs.An interferometer---no matter how clever the design---cannot reveal both the wave and the particle behavior of a quantum system. This fundamental idea has been captured by inequalities, so-called wave-particle duality relations (WPDRs), that upper bound the sum of the fringe visibility (wave behavior) and path distinguishability (particle behavior). Another fundamental idea is Heisenberg's uncertainty principle, stating that some pairs of observables cannot be known simultaneously. Recent work has unified these two principles for two-path interferometers. Here we extend this unification to $n$-path interferometers, showing that WPDRs correspond to a modern formulation of the uncertainty principle stated in terms of entropies. Furthermore, our unification provides a framework for solving an outstanding problem of how to formulate universally valid WPDRs for interferometers with more than two paths, and we employ this framework to derive some novel WPDRs.

arXiv:1512.09081Physical Review AJun 9, 201665 citations

THE WAVE-PARTICLE DUALITY

University of Arkansas Press eBooksSep 7, 20170 citations

Wave-particle superposition of distinct atomic spin excitations

Wei Zhang, Dong-Sheng Ding, Ming‐Xin Dong +4 more

Wave-particle duality is the most essential nature of light, and the fact that the detection apparatus determines the observed wave or particle behavior is one of the most counterintuitive features of quantum mechanics. Recent progress in this direction has revealed novel and peculiar phenomena of photonic wave-particle morphing and wave-particle superposition, which provide a deep understanding of the wave-particle duality for photons. However, it remains an open question whether this new conception can be extended to a more complex physical system, such as an atomic system. We here report an experimental realization of the wave-particle superposition of distinct atomic spin excitations in a cold atomic ensemble by using multiplexed quantum memory. The quantum behavior of wave-particle superposition for matter is observed and verified. Our scheme further provides a benchmark understanding of the wave-particle duality in matter systems.Wave-particle duality is the most essential nature of light, and the fact that the detection apparatus determines the observed wave or particle behavior is one of the most counterintuitive features of quantum mechanics. Recent progress in this direction has revealed novel and peculiar phenomena of photonic wave-particle morphing and wave-particle superposition, which provide a deep understanding of the wave-particle duality for photons. However, it remains an open question whether this new conception can be extended to a more complex physical system, such as an atomic system. We here report an experimental realization of the wave-particle superposition of distinct atomic spin excitations in a cold atomic ensemble by using multiplexed quantum memory. The quantum behavior of wave-particle superposition for matter is observed and verified. Our scheme further provides a benchmark understanding of the wave-particle duality in matter systems.

Physical Review ADec 20, 20182 citations

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-path interferometers, showing that WPDRs correspond to a modern formulation of the uncertainty principle stated in terms of entropies. Furthermore, our unification provides a framework for solving an outstanding problem of how to formulate universally valid WPDRs for interferometers with more than two paths, and we employ this framework to derive some novel WPDRs.