Abstract Wave-particle duality is an inherent characteristic of microscopic systems, which exhibit both wave-like and particle-like behaviors depending on the experimental setup. On the other hand, quantum coherence refers to the ability of a quantum state to preserve its superposition despite interactions and thermalization effects. In this study, we experimentally investigate a tighter wave-particle duality based on quantum coherence. We construct a heralded single-photon source and use the expect values of Pauli operators to quantify the interferometric visibility and path distinguishability of photons. By employing quantum state tomography, we reconstruct the density matrix of the quantum state and assess its quantum coherence. Our results provide experimental evidence for the tighter wave-particle duality based on quantum coherence.
Abstract Wave-particle duality is an inherent characteristic of microscopic systems, which exhibit both wave-like and particle-like behaviors depending on the experimental setup. On the other hand, quantum coherence refers to the ability of a quantum state to preserve its superposition despite interactions and thermalization effects. In this study, we experimentally investigate a tighter wave-particle duality based on quantum coherence. We construct a heralded single-photon source and use the expect values of Pauli operators to quantify the interferometric visibility and path distinguishability of photons. By employing quantum state tomography, we reconstruct the density matrix of the quantum state and assess its quantum coherence. Our results provide experimental evidence for the tighter wave-particle duality based on quantum coherence.
The wave-particle duality has been said to contain the entire mystery of quantum mechanics. Many delayed-choice experiments have been performed to further understand the wave-particle duality. Here, we reveal some flaws in the known interference theories by comparing the theoretical predictions with the experimental facts and show that the presence of media is a necessary condition for interference of single photons, a photon interferes with other photon via microscopic particles in the interface of media, and the wave-like property of a photon originates from interaction between the photon and media; the particle property is the inherent characteristic of a photon, and the wave-like behavior of a photon always accompanies the particle behavior; the coherent time of single photons cannot be longer than the lifetime of the polarized states of the microscopic particles. Interference of single photons is interpreted properly, and the conundrum of the wave-particle duality is well solved.
Wave-particle duality, a fundamental principle of quantum mechanics, encapsulates the complementary relationship between the wave and particle behaviors of quantum systems. In this paper, we treat quantum coherence and classical distinguishability as complementary resources and uncover a novel duality relation, which is explored through quantum state discrimination under incoherent operations, extending beyond typical interference scenarios. We prove that in an ensemble of mutually orthogonal pure states, the sum of ``co-bits,'' quantifying the coherence preserved under incoherent free operations, and classical bits, representing the distinguishability extracted via quantum state discrimination, is bounded. This coherence-distinguishability duality relation exposes an inherent tradeoff between the simultaneous preservation of a system's quantum coherence (wavelike property) and the extraction of its classical distinguishability (particlelike property). Our findings provide a fresh perspective on wave-particle duality through quantum resource theories, offering complementary insights into manipulating quantum and classical resources, with implications for quantum foundations and quantum technologies.
Abstract Quantum coherence stemming from the superposition behaviour of a particle beyond the classical realm, serves as one of the most fundamental features in quantum mechanics. The wave-particle duality phenomenon, which shares the same origin, has a strong relationship with quantum coherence. Recently, an elegant relation between quantum coherence and path information has been theoretically derived. Here, we experimentally test such new duality by l1-norm measure and the minimum-error state discrimination. We prepare three classes of two-photon states encoded in polarisation degree of freedom, with one photon serving as the target and the other photon as the detector. We observe that wave-particle-like complementarity and Bagan’s equality, defined by the duality relation between coherence and path information, is well satisfied. Our results may shed new light on the original nature of wave-particle duality and on the applications of quantum coherence as a fundamental resource in quantum technologies.
Wave-particle duality is the most fundamental description of the nature of a quantum object, which behaves like a classical particle or wave depending on the measurement apparatus. On the other hand, entanglement represents nonclassical correlations of composite quantum systems, being also a key resource in quantum information. Despite the very recent observations of wave-particle superposition and entanglement, whether these two fundamental traits of quantum mechanics can emerge simultaneously remains an open issue. Here we introduce and experimentally realize a scheme that deterministically generates entanglement between the wave and particle states of two photons. The elementary tool allowing this achievement is a scalable single-photon setup which can be in principle extended to generate multiphoton wave-particle entanglement. Our study reveals that photons can be entangled in their dual wave-particle behavior and opens the way to potential applications in quantum information protocols exploiting the wave-particle degrees of freedom to encode qubits.Here the authors experimentally realize a scheme that deterministically generates entanglement between the wave and particle states of two photons using a scalable all-optical scheme. They achieve this result by first showing generation of controllable single-photon wave-particle superposition states.
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.
According to the relevant theories on duality relation, the summation of the extractable information of a quanton’s wave and particle properties, which are characterized by interference visibility V and path distinguishability D, respectively, is limited. However, this relation is violated upon quantum superposition between the wave-state and particle-state of the quanton, which is caused by the quantum beamsplitter (QBS). Along another line, recent studies have considered quantum coherence C in the l1-norm measure as a candidate for the wave property. In this study, we propose an interferometer with a quantum which-path detector (QWPD) and examine the generalized duality relation based on C. We find that this relationship still holds under such a circumstance, but the interference between these two properties causes the full-particle property to be observed when the QWPD system is partially present. Using a pair of polarization-entangled photons, we experimentally verify our analysis in the two-path case. This study extends the duality relation between coherence and path information to the quantum case and reveals the effect of quantum superposition on the duality relation.