scholarly journals Wave-Particle Duality Relation with a Quantum Which-Path Detector

Entropy ◽  
2021 ◽  
Vol 23 (1) ◽  
pp. 122 ◽  
Author(s):  
Dongyang Wang ◽  
Junjie Wu ◽  
Jiangfang Ding ◽  
Yingwen Liu ◽  
Anqi Huang ◽  
...  
Keyword(s):  
Quantum Coherence ◽  
Duality Relation ◽  
Particle State ◽  
L1 Norm ◽  
Quantum Superposition ◽  
Wave State ◽  
Particle Properties ◽  
Wave Particle Duality ◽  
Wave Property ◽  
Particle Property

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.

scholarly journals New Interpretations of The State Function of An Elementary Particle Based On The Origin of Quantum Probability

2021 ◽  
Author(s):  
Shuming Wen
Keyword(s):  
Quantum Probability ◽  
The State ◽  
Particle State ◽  
State Function ◽  
Quantum Superposition ◽  
Wave State ◽  
Heisenberg Uncertainty Principle ◽  
Quantum Tunnelling ◽  
Wave Particle Duality ◽  
Objective System

Abstract The theoretical results of quantum mechanics (QM) have been verified by experiments, but the probabilistic Copenhagen interpretation is still controversial, and many counterintuitive phenomena are still difficult to understand. To trace the origin of probability in QM, we construct the state function of a multiparticle quantum objective system and find that the probability in QM originates from the particle number distribution rate in a unit volume near position r at time t in the multiparticle quantum objective system. Based on the origin of probability, We find that the state function of the particle has precise physical meaning; that is, the particle periodically and alternately exhibits the particle state and wave state in time and space, obtain the localized and nonlocalized spatiotemporal range of the particle, the apparent trajectory of the particle motion. Based on this, through rigorous mathematical derivation and analysis, we propose new physical interpretations of the quantum superposition state, wave-particle duality, the double-slit experiment, the Heisenberg uncertainty principle, and the quantum tunnelling effect, and these interpretations are physically logical and not counterintuitive.

scholarly journals Origin of Probability in Quantum Mechanics and the Physical Interpretation of the Wave Function

2021 ◽  
Author(s):  
Shuming Wen
Keyword(s):  
Quantum Mechanics ◽  
The State ◽  
Particle State ◽  
State Function ◽  
Quantum Superposition ◽  
Wave State ◽  
Heisenberg Uncertainty Principle ◽  
Quantum Tunnelling ◽  
Wave Particle Duality ◽  
Objective System

Abstract The theoretical results of quantum mechanics (QM) have been verified by experiments, but the probabilistic Copenhagen interpretation is still controversial, and many counterintuitive phenomena are still difficult to understand. To trace the origin of probability in QM, we construct the state function of a multiparticle quantum objective system and find that the probability in QM originates from the particle number distribution rate in a unit volume near position r at time t in the multiparticle quantum objective system. Based on the origin of probability, We find that the state function of the particle has precise physical meaning; that is, the particle periodically and alternately exhibits the particle state and wave state in time and space, obtain the localized and nonlocalized spatiotemporal range of the particle, the apparent trajectory of the particle motion. Based on this, through rigorous mathematical derivation and analysis, we propose new physical interpretations of the quantum superposition state, wave-particle duality, the double-slit experiment, the Heisenberg uncertainty principle, and the quantum tunnelling effect, and these interpretations are physically logical and not counterintuitive.

scholarly journals Quantum Computers - An Emerging Cybersecurity Threat

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Dajana Jelčić Dubček
Keyword(s):  
Information Processing ◽  
Quantum Coherence ◽  
Quantum Physics ◽  
Quantum Computers ◽  
Practical Implementation ◽  
Quantum Superposition ◽  
Processing And Storage ◽  
And Storage ◽  
Superposition Of States

Quantum computational supremacy may potentially endanger the current cryptographic protection methods. Although quantum computers are still far from a practical implementation in information processing and storage, they should not be overlooked in the context of cybersecurity. Quantum computers operate with qubits - units of information that are governed by the fundamental principles of quantum physics, such as quantum superposition of states and quantum coherence. In order to address the new challenge that quantum computers pose to cybersecurity, the very principles of their operation have to be understood and are overviewed in this contribution.

scholarly journals Investigating Quantum Coherence by Negative Excursions of the Wigner Quasi-Distribution

2019 ◽  
Vol 9 (7) ◽  
pp. 1344 ◽  
Author(s):  
Mauro Ballicchia ◽  
David Ferry ◽  
Mihail Nedjalkov ◽  
Josef Weinbub
Keyword(s):  
Wave Function ◽  
Quantum Interference ◽  
Quantum Coherence ◽  
Quantum Communication ◽  
Electron System ◽  
Physical Problem ◽  
Quantum Superposition ◽  
Negative Part ◽  
Initial Momentum ◽  
The Past

Quantum information and quantum communication are both strongly based on concepts of quantum superposition and entanglement. Entanglement allows distinct bodies, that share a common origin or that have interacted in the past, to continue to be described by the same wave function until evolution is coherent. So, there is an equivalence between coherence and entanglement. In this paper, we show the relation between quantum coherence and quantum interference and the negative parts of the Wigner quasi-distribution, using the Wigner signed-particle formulation. A simple physical problem consisting of electrons in a nanowire interacting with the potential of a repulsive dopant placed in the center of it creates a quasi two-slit electron system that separates the wave function into two entangled branches. The analysis of the Wigner quasi-distribution of this problem establishes that its negative part is principally concentrated in the region after the dopant between the two entangled branches, maintaining the coherence between them. Moreover, quantum interference is shown in this region both in the positive and in the negative part of the Wigner function and is produced by the superposition of Wigner functions evaluated at points of the momentum space that are symmetric with respect to the initial momentum of the injected electrons.

scholarly journals A quantum interpretation of the physical basis of mass–energy equivalence

2020 ◽  
Vol 34 (18) ◽  
pp. 2030002
Author(s):  
Donald C. Chang
Keyword(s):  
Wave Model ◽  
Physical Basis ◽  
Careful Examination ◽  
Newtonian Mechanics ◽  
Mass Energy ◽  
Principle Of Relativity ◽  
Energy Equivalence ◽  
Wave Particle Duality ◽  
Wave Property ◽  
Quantum Interpretation

We know energy and mass of a particle can be connected by [Formula: see text]. What is the physical basis of this relation? Historically, it was thought to be based on the principle of relativity (PR). A careful examination of the literature, however, indicated that this understanding is not true. Einstein did not derive this relation from PR. Instead, his argument was mainly based on thought experiments, which focused on the similarity between radiation and matter. Following this hint, we suspect that the mass–energy equivalence could be based on the quantum property of wave–particle duality. We know photon and electron can behave as a particle as well as a wave. Such a wave property could make the particle behave differently from Newtonian mechanics. Indeed, using a wave model which treats particles as excitations of the vacuum, we show that the mass–energy equivalence relation can be directly derived based on the quantum relations of Planck and de Broglie. This wave hypothesis has several advantages; not only can it explain naturally why particles can be created in the vacuum; it also predicts that a particle cannot travel faster than the speed of light. This hypothesis can also be tested in experiment.

scholarly journals Wildfire Smoke Particle Properties and Evolution, From Space-Based Multi-Angle Imaging II: The Williams Flats Fire during the FIREX-AQ Campaign

2020 ◽  
Vol 12 (22) ◽  
pp. 3823
Author(s):  
Katherine T. Junghenn Noyes ◽  
Ralph A. Kahn ◽  
James A. Limbacher ◽  
Zhanqing Li ◽  
Marta A. Fenn ◽  
...  
Keyword(s):  
Particle Size ◽  
Biomass Burning ◽  
In Situ Measurements ◽  
Statistical Characterization ◽  
Smoke Particle ◽  
Particle Properties ◽  
In Situ Data ◽  
Particle Property ◽  
Aircraft Data

Although the characteristics of biomass burning events and the ambient ecosystem determine emitted smoke composition, the conditions that modulate the partitioning of black carbon (BC) and brown carbon (BrC) formation are not well understood, nor are the spatial or temporal frequency of factors driving smoke particle evolution, such as hydration, coagulation, and oxidation, all of which impact smoke radiative forcing. In situ data from surface observation sites and aircraft field campaigns offer deep insight into the optical, chemical, and microphysical traits of biomass burning (BB) smoke aerosols, such as single scattering albedo (SSA) and size distribution, but cannot by themselves provide robust statistical characterization of both emitted and evolved particles. Data from the NASA Earth Observing System’s Multi-Angle Imaging SpectroRadiometer (MISR) instrument can provide at least a partial picture of BB particle properties and their evolution downwind, once properly validated. Here we use in situ data from the joint NOAA/NASA 2019 Fire Influence on Regional to Global Environments Experiment-Air Quality (FIREX-AQ) field campaign to assess the strengths and limitations of MISR-derived constraints on particle size, shape, light-absorption, and its spectral slope, as well as plume height and associated wind vectors. Based on the satellite observations, we also offer inferences about aging mechanisms effecting downwind particle evolution, such as gravitational settling, oxidation, secondary particle formation, and the combination of particle aggregation and condensational growth. This work builds upon our previous study, adding confidence to our interpretation of the remote-sensing data based on an expanded suite of in situ measurements for validation. The satellite and in situ measurements offer similar characterizations of particle property evolution as a function of smoke age for the 06 August Williams Flats Fire, and most of the key differences in particle size and absorption can be attributed to differences in sampling and changes in the plume geometry between sampling times. Whereas the aircraft data provide validation for the MISR retrievals, the satellite data offer a spatially continuous mapping of particle properties over the plume, which helps identify trends in particle property downwind evolution that are ambiguous in the sparsely sampled aircraft transects. The MISR data record is more than two decades long, offering future opportunities to study regional wildfire plume behavior statistically, where aircraft data are limited or entirely lacking.

scholarly journals The Tightness of Multipartite Coherence from Spectrum Estimation

Entropy ◽  
2021 ◽  
Vol 23 (11) ◽  
pp. 1519
Author(s):  
Qi-Ming Ding ◽  
Xiao-Xu Fang ◽  
He Lu
Keyword(s):  
Quantum State ◽  
Quantum Coherence ◽  
Large Scale ◽  
Spectrum Estimation ◽  
L1 Norm ◽  
Cluster States ◽  
State Reconstruction ◽  
Geometric Measure ◽  
Quantum State Reconstruction ◽  
Linear Cluster

Detecting multipartite quantum coherence usually requires quantum state reconstruction, which is quite inefficient for large-scale quantum systems. Along this line of research, several efficient procedures have been proposed to detect multipartite quantum coherence without quantum state reconstruction, among which the spectrum-estimation-based method is suitable for various coherence measures. Here, we first generalize the spectrum-estimation-based method for the geometric measure of coherence. Then, we investigate the tightness of the estimated lower bound of various coherence measures, including the geometric measure of coherence, the l1-norm of coherence, the robustness of coherence, and some convex roof quantifiers of coherence multiqubit GHZ states and linear cluster states. Finally, we demonstrate the spectrum-estimation-based method as well as the other two efficient methods by using the same experimental data [Ding et al. Phys. Rev. Research 3, 023228 (2021)]. We observe that the spectrum-estimation-based method outperforms other methods in various coherence measures, which significantly enhances the accuracy of estimation.

scholarly journals Coherence, Interference and Visibility

Quanta ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 24-35 ◽  
Author(s):  
Tabish Qureshi
Keyword(s):  
Quantum Coherence ◽  
Wave Nature ◽  
Duality Relations ◽  
Wave Particle Duality ◽  
The Subject

The interference observed for a quanton, traversing more than one path, is believed to characterize its wave nature. Conventionally, the sharpness of interference has been quantified by its visibility or contrast, as defined in optics. Based on this visibility, wave-particle duality relations have been formulated for two-path interference. However, as one generalizes the situation to multi-path interference, it is found that conventional interference visibility is not a good quantifier. A recently introduced measure of quantum coherence has been shown to be a good quantifier of the wave nature. The subject of quantum coherence, in relation to the wave nature of quantons and to interference visibility, is reviewed here. It is argued that coherence can be construed as a more general form of interference visibility, if the visibility is measured in a different manner, and not as contrast.Quanta 2019; 8: 24–35.

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