Journal of Physics Communications最新文献

{"title":"Deriving measurement collapse using zeta function regularisation and speculative measurement theory","authors":"Mark Stander","doi":"10.1088/2399-6528/ad6a4c","DOIUrl":"https://doi.org/10.1088/2399-6528/ad6a4c","url":null,"abstract":"This paper shows how an application of zeta function regularisation to a physical model of quantum measurement yields a solution to the problem of wavefunction collapse. Realistic measurement dynamics based on a particle becoming non-isolated are introduced and, based on this, an outcome function is derived using the method of maximum entropy. It is shown how regularisation of an information theoretic quantity related to this outcome function leads to apparent collapse of the wavefunction. The physical principles and key assumptions that underlie this theory are discussed. Some possible experimental approaches are described.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"15 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142247835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zinc oxide behavior in CO detection as a function of thermal treatment time","authors":"M P Munguía-Martín, D Sánchez-Campos, D Mendoza-Anaya, T V K Karthik, L S Villaseñor-Cerón, M I Reyes-Valderrama and V Rodríguez-Lugo","doi":"10.1088/2399-6528/ad777b","DOIUrl":"https://doi.org/10.1088/2399-6528/ad777b","url":null,"abstract":"Gas sensors are crucial for safety and well-being in various environments. Zinc oxide (ZnO) gas sensors are notable for their broad gas detection capabilities. In this study, ZnO structures were synthesized by optimized chemical precipitation method with urea, followed by a thermal treatment at 500 °C for 5, 10, 13, and 15 h. The microstructural, morphological, and CO sensing properties were examined. X-ray Diffraction analysis confirmed the hexagonal wurtzite phase. Crystallite size increased from 17.28 to 18.95 nm with longer thermal treatment times. Scanning Electron Microscopy revealed spherical and semi-spherical agglomerates with middle distribution of particle sizes ranging from 140 to 445 nm. The synthesized ZnO structures were evaluated as gas sensors for CO detection. Response time, recovery time, and sensor response were analyzed in a CO atmosphere at 100, 200, and 300 °C. The sample with thermal treatment for 13 h exhibited the lowest Tr of 2.43 s at a concentration of 166 parts per million and 300 °C. The Tr reduction correlated with a ZnO decrease particle size observed with longer thermal treatment times, highlighting the influence of particle size on sensor performance.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"213 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Teleportation of a qubit using quasi-Bell states","authors":"Isiaka Aremua and Laure Gouba","doi":"10.1088/2399-6528/ad74c6","DOIUrl":"https://doi.org/10.1088/2399-6528/ad74c6","url":null,"abstract":"In this paper, we study the exotic Landau problem at the classical level where two conserved quantities are derived. At the quantum level, the corresponding quantum operators of the conserved quantities provide two oscillator representations from which we derive two Boson Fock spaces. Using the normalized coherent states which are the minimum uncertainty states on noncommutative configuration space isomorphic to each of the boson Fock space, we form entangled coherent states which are Bell- like states labeled quasi-Bell states. The effect of non-maximality of a quasi-Bell state based quantum channel is investigated in the context of a teleportation of a qubit.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"40 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The n-shot classical capacity of the quantum erasure channel","authors":"Matteo Rosati","doi":"10.1088/2399-6528/ad6f6b","DOIUrl":"https://doi.org/10.1088/2399-6528/ad6f6b","url":null,"abstract":"We compute the <italic toggle=\"yes\">n</italic>-shot classical capacity of the quantum erasure channel, providing upper bounds and almost-matching lower bounds for it, the latter achievable via large-minimum-distance classical linear codes for any <italic toggle=\"yes\">n</italic>. The protocols are in full product form, i.e. no entanglement is needed either at the encoder or decoder to attain the capacity, and they explicitly adapt to the transition between different error regimes as the erasure probability increases. Finally, we show that our upper and lower bounds on the capacity are tighter than those obtainable from the general theory of finite-size capacity via generalized divergences.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"74 39 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anisotropic effects in the nondipole relativistic photoionization of hydrogen","authors":"J E Vembe, M Førre","doi":"10.1088/2399-6528/ad6e52","DOIUrl":"https://doi.org/10.1088/2399-6528/ad6e52","url":null,"abstract":"In the nonrelativistic and dipole regime of multiphoton ionization, spherical symmetry in all but the polarization direction of the laser pulse ensures that directional dependency in the photoelectron spectra is limited to the laser polarization direction, with the final distribution exhibiting no asymmetry along the propagation direction of the laser. When relativistic effects and spatial dependency in the external potential are accounted for however, the addition of time dilation and radiation pressure both impose anisotropic effects. Previously we have found that nondipole effects induce a redshift in the photoelectron energy distribution, while conversely relativistic effects induce a blueshift, with the net effect of an apparent near-cancellation of the two. In this work we study these effects further. By examining photoelectron momentum distributions acquired from simulations with the time-dependent Dirac equation we propose explanatory models for both phenomena and present a simplified model of the shifts as a function of the angle relative to the propagation direction of the laser pulse. It is found that both nondipole and relativistic effects must be accounted for on an equal footing in order to correctly describe the photoelectron momentum distribution in the high-intensity regime.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"13 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the mathematical quantification of inequality in probability distributions","authors":"R Rajaram, N Ritchey, B Castellani","doi":"10.1088/2399-6528/ad6ad1","DOIUrl":"https://doi.org/10.1088/2399-6528/ad6ad1","url":null,"abstract":"A fundamental challenge in the study of probability distributions is the quantification of inequality that is inherently present in them. Some parts of the distribution are more probable and some others are not, and we are interested in the quantification of this inequality through the lens of mathematical diversity, which is a new approach to studying inequality. We offer a theoretical advance, based on case-based entropy and slope of diversity, which addresses inequality for arbitrary probability distributions through the concept of mathematical diversity. Our approach is useful in three important ways: (1) it offers a universal way to measure inequality in arbitrary probability distributions based purely on the entropic uncertainty that is inherent in them and nothing else; (2) it allows us to compare the degree of inequality of arbitrary parts of any distribution (not just tails) and entire distributions alike; and (3) it can glean out empirical rules similar to the 80/20 rule, not just for the power law but for any given distribution or its parts thereof. The techniques shown in this paper demonstrate a more general machinery to quantify inequality, compare the degree of inequality of parts or whole of general distributions, and prove or glean out empirical rules for general distributions based on mathematical diversity. We demonstrate the utility of this new machinery by applying it to the power law, the exponential and the geometric distributions. The 60 − 40 rule of restricted diversity states that 60 percent or more of cases following a power law (or more generally a right skewed distribution) reside within 40 percent or less of the lower bound of Shannon equivalent equi-probable (SEE) types as measured by case-based entropy. In this paper, we prove the 60 − 40 rule for power law distributions analytically. We also show that in all power law distributions, the second half of the distribution is at least 4 times more uniformly distributed as the first. Lastly, we also show a scale-free way of comparing probability distributions based on the idea of mathematical diversity of parts of a distribution. We use this comparison technique to compare the exponential and power law distribution, and obtain the exponential distribution as an entropic limit of the power law distribution. We also demonstrate that the machinery is applicable to discrete distributions by proving a general result regarding the comparison of parts of the geometric distribution.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"13 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature and medium structurization effect on spontaneous evolution of domains and bubbles in magnetic nanostructures","authors":"Andrzej Janutka","doi":"10.1088/2399-6528/ad61bb","DOIUrl":"https://doi.org/10.1088/2399-6528/ad61bb","url":null,"abstract":"Spontaneous evolutions of domains in magnetic nanowires and of magnetic bubbles in open ferromagnetic nanolayers are investigated using micromagnetic simulations. We compare temperature dependent dynamics of domain wall (DW) systems in Permalloy (Py) nanowires and systems of chiral DWs in ultra-thin nanowires with perpendicular magnetic anisotropy (PMA) and Dzyaloshinskii-Moriya interaction (DMI). In Py nanowires DWs collide and, in majority of cases, the collision leads to the DW annihilation in disagreement with the expectation of topological protection of sums of all the magnetic charges attached to the nanowire edges which are carried by DWs. For our purpose of discussing the DW collision in the presence of thermal excitations, we revisit the problem of field-driven collisions of DWs in Py nanowires at zero temperature. We claim that thermal fluctuations can counteract the collision-induced annihilation of DWs, thought further improvement of stabilization of domain structures is achievable via structurization of the magnetic nanowires (dividing them into grains). In PMA-DMI nanowires, thermally-excited chiral DWs can be randomly approaching or moving away while not being annihilated. A problem related to the motion of chiral DWs is the spontaneous motion of magnetic bubbles in open PMA-DMI planes. The magnetic bubbles expand or shrink to vanishing dependent on strength of the DMI interaction. Such a motion appears to be be strongly influenced by temperature and by structural discontinuities of the magnetic layer.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"62 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141778041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-unique detailed constructions of Curzon-Ahlborn cycle on thermodynamic plane","authors":"Yuki Izumida","doi":"10.1088/2399-6528/ad5f0f","DOIUrl":"https://doi.org/10.1088/2399-6528/ad5f0f","url":null,"abstract":"The Curzon-Ahlborn (CA) cycle is a paradigmatic model of endoreversible heat engines, which yields the so-called CA efficiency as the efficiency at maximum power. Due to the arbitrariness of the relationship between the steady temperature and the time taken for the isothermal process of the CA cycle, the constructions of the CA cycle on the thermodynamic plane are not unique. Here, we give some of the detailed constructions of the CA cycle on the thermodynamic plane, using an ideal gas as a working substance. It is shown that these constructions are equal to each other in the maximum power regime in the sense that they achieve the best trade-off between the work and the inverse cycle-time, known as the Pareto front in multi-objective optimization problems.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"32 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141721054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anomalous to normal dispersion nonlinear optical dephasing switch in electromagnetically induced transparency using a Kerr effect","authors":"Ayyappan J and Beena T","doi":"10.1088/2399-6528/ad5b39","DOIUrl":"https://doi.org/10.1088/2399-6528/ad5b39","url":null,"abstract":"The atomic decoherence effect (DE) on a Kerr nonlinear (KNL) electromagnetically induced transparency (EIT)is studied in a Δ system. The DE between the ground state hyperfine levels is caused by the dephasing rate γd which dramatically modifies the medium response. It controls the normal dispersive region which shows steep positive slopes for linear response at the line center while the nonlinear response experiences steep negative slopes for low γd. The microwave field strength and γd modify the nonlinear response from the anomalous dispersion to normal dispersion. The calculations show that room-temperature atoms are used to quantify the quantum interference (QI) on linear and nonlinear absorption with γd. The EIT spectrum explores the understanding of the subluminal and superluminal wave propagation of probe signal and this study opens a new pathway for the understanding of the QI devices and their nonlinearities based on EIT.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"41 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141550529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Roles of energy and entropy in multiscale dynamics and thermodynamics","authors":"Miroslav Grmela","doi":"10.1088/2399-6528/ad5b3a","DOIUrl":"https://doi.org/10.1088/2399-6528/ad5b3a","url":null,"abstract":"Multiscale thermodynamics is a theory of relations among levels of description. Energy and entropy are its two main ingredients. Their roles in the time evolution describing approach of a level (starting level) to another level involving less details (target level) is examined on several examples, including the level on which macroscopic systems are seen as composed of microscopic particles, mesoscopic levels as kinetic theory of ideal and van der Waals gases, fluid mechanics, the level of chemical kinetics, and the level of equilibrium thermodynamics. The entropy enters the emergence of the target level in two roles. It expresses internal energy, that is the part of the energy that cannot be expressed in terms of the state variables used on the starting level, and it reveals emerging features characterizing the target level by sweeping away unimportant details. In the case when the target level is a mesoscopic level involving time evolution the roles of the energy and the entropy is taken by two different potentials that are related to their rates.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"25 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141522714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}