Pub Date : 2023-07-01DOI: 10.12693/aphyspola.144.7
Y. Zhong, S. Du, S. Yao, L. Peng, J. Chen, L. Sang, J. Lin, X. Liu
Using a finite element method to numerically solve the time-dependent Ginzburg–Landau equations, we studied the influence of an inhomogeneous magnetic field on the dynamic behavior of vortex–antivortex chains in the superconductor/ferromagnet bilayer structures. Our results show that the coupling effect of superconductor/ferromagnet structures manifests as the vortex–antivortex pairs interaction. The coupling effect increases with the increasing level of inhomogeneity of the magnetic field. The periodic motion of the vortex–antivortex chains leads to the periodic oscillations of the magnetization and superconducting current in the superconductor film. The frequency of oscillations is adjusted by the inhomogeneous magnetic field and the external driving current.
{"title":"Influence of Inhomogeneous Magnetic Field on Dynamic Behavior of Vortex-Antivortex Chains in the Superconductor/Ferromagnet Bilayer Structures","authors":"Y. Zhong, S. Du, S. Yao, L. Peng, J. Chen, L. Sang, J. Lin, X. Liu","doi":"10.12693/aphyspola.144.7","DOIUrl":"https://doi.org/10.12693/aphyspola.144.7","url":null,"abstract":"Using a finite element method to numerically solve the time-dependent Ginzburg–Landau equations, we studied the influence of an inhomogeneous magnetic field on the dynamic behavior of vortex–antivortex chains in the superconductor/ferromagnet bilayer structures. Our results show that the coupling effect of superconductor/ferromagnet structures manifests as the vortex–antivortex pairs interaction. The coupling effect increases with the increasing level of inhomogeneity of the magnetic field. The periodic motion of the vortex–antivortex chains leads to the periodic oscillations of the magnetization and superconducting current in the superconductor film. The frequency of oscillations is adjusted by the inhomogeneous magnetic field and the external driving current.","PeriodicalId":7164,"journal":{"name":"Acta Physica Polonica A","volume":"12 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84917648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-01DOI: 10.12693/aphyspola.144.38
N. C. Toan, N.V. Hung
A semi-classical anharmonic correlated Einstein model of hcp crystals is derived for the high-order expanded Debye–Waller factors and extended X-ray absorption fine structure. The many-body effect is included in this model based on the contributions of the first shell near neighbors of the absorber and backscatter atoms. The analytical expressions of Debye–Waller factors presented in terms of cumulant expansion up to the fourth order yield results based on the classical theory corrected for its absence of zero-point vibration. The anharmonic many-body effect effective potential is derived which includes the Morse potential for describing the single-pair atomic interactions. A method of providing all extended X-ray absorption fine structure quantities is created, correcting the absence of zero-point vibration in classical theory, combining it with the quantum one based on only the second cumulant. The derived model has the advantage of including both classical and quantum effects. The numerical results of all considered quantities of Zn (hcp) are found to be in good agreement with the experimental values.
{"title":"Semi-classical Anharmonic Correlated Einstein Model Debye-Waller Factors and EXAFS of Hcp Crystals","authors":"N. C. Toan, N.V. Hung","doi":"10.12693/aphyspola.144.38","DOIUrl":"https://doi.org/10.12693/aphyspola.144.38","url":null,"abstract":"A semi-classical anharmonic correlated Einstein model of hcp crystals is derived for the high-order expanded Debye–Waller factors and extended X-ray absorption fine structure. The many-body effect is included in this model based on the contributions of the first shell near neighbors of the absorber and backscatter atoms. The analytical expressions of Debye–Waller factors presented in terms of cumulant expansion up to the fourth order yield results based on the classical theory corrected for its absence of zero-point vibration. The anharmonic many-body effect effective potential is derived which includes the Morse potential for describing the single-pair atomic interactions. A method of providing all extended X-ray absorption fine structure quantities is created, correcting the absence of zero-point vibration in classical theory, combining it with the quantum one based on only the second cumulant. The derived model has the advantage of including both classical and quantum effects. The numerical results of all considered quantities of Zn (hcp) are found to be in good agreement with the experimental values.","PeriodicalId":7164,"journal":{"name":"Acta Physica Polonica A","volume":"29 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78208915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.12693/APhysPolA.143.S95
Tomasz Linowski, Lukasz Rudnicki
We use the reduced state of the field formalism [Entropy 21, 705 (2019)] to derive conditions under which a Bogoliubov transformation can be considered semi-classical. We apply this result to the dynamical Casimir effect in a moving medium [Phys. Rev. A 78, 042109 (2008)], discussing its classical and quantum features.
{"title":"Classicality of the Bogoliubov Transformations and the Dynamical Casimir Effect Through the Reduced State of the Field","authors":"Tomasz Linowski, Lukasz Rudnicki","doi":"10.12693/APhysPolA.143.S95","DOIUrl":"https://doi.org/10.12693/APhysPolA.143.S95","url":null,"abstract":"We use the reduced state of the field formalism [Entropy 21, 705 (2019)] to derive conditions under which a Bogoliubov transformation can be considered semi-classical. We apply this result to the dynamical Casimir effect in a moving medium [Phys. Rev. A 78, 042109 (2008)], discussing its classical and quantum features.","PeriodicalId":7164,"journal":{"name":"Acta Physica Polonica A","volume":"155 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77984126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.12693/APhysPolA.143.S123
J. Kijowski
A geometric construction of the arrival time in conventional quantum mechanics is presented. It is based on a careful mathematical analysis of different quantization procedures for classical observables as functions of positions and momenta. A class of observables is selected which possess a unique (if any) quantized version. A simple criterion for existence of such a quantized version is formulated. These mathematical results are then applied to the classical"arrival time"observable.
{"title":"Arrival Time in Quantum Mechanics (Demonstrated in Geometrical Order)","authors":"J. Kijowski","doi":"10.12693/APhysPolA.143.S123","DOIUrl":"https://doi.org/10.12693/APhysPolA.143.S123","url":null,"abstract":"A geometric construction of the arrival time in conventional quantum mechanics is presented. It is based on a careful mathematical analysis of different quantization procedures for classical observables as functions of positions and momenta. A class of observables is selected which possess a unique (if any) quantized version. A simple criterion for existence of such a quantized version is formulated. These mathematical results are then applied to the classical\"arrival time\"observable.","PeriodicalId":7164,"journal":{"name":"Acta Physica Polonica A","volume":"5 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87477460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.12693/APhysPolA.143.S18
A. Bechler, F. C. V'elez, K. Krajewska, J. Z. Kami'nski
Vortex pattern formation in electron-positron pair creation from vacuum by a time-dependent electric field of linear polarization is analyzed. It is demonstrated that in such scenario the momentum distributions of created particles exhibit vortex-antivortex pairs. Their sensitivity to the laser field parameters such as the field frequency and intensity is also studied. Specifically, it is shown that with increasing field frequency accross the one-photon threshold additional vortex-antivortex pairs appear. Their location in the momentum space is consistent with a general threshold behavior of probability distributions of created electrons (positrons). Namely, while for small field frequencies the particles tend to be created along the field polarization direction, for large enough frequencies they are predominantly generated in the perpendicular direction. Such change in longitudinal and transverse momentum sharing of created particles occurs accross the one-photon threshold.
{"title":"Vortex Structures and Momentum Sharing in Dynamic Sauter-Schwinger Process","authors":"A. Bechler, F. C. V'elez, K. Krajewska, J. Z. Kami'nski","doi":"10.12693/APhysPolA.143.S18","DOIUrl":"https://doi.org/10.12693/APhysPolA.143.S18","url":null,"abstract":"Vortex pattern formation in electron-positron pair creation from vacuum by a time-dependent electric field of linear polarization is analyzed. It is demonstrated that in such scenario the momentum distributions of created particles exhibit vortex-antivortex pairs. Their sensitivity to the laser field parameters such as the field frequency and intensity is also studied. Specifically, it is shown that with increasing field frequency accross the one-photon threshold additional vortex-antivortex pairs appear. Their location in the momentum space is consistent with a general threshold behavior of probability distributions of created electrons (positrons). Namely, while for small field frequencies the particles tend to be created along the field polarization direction, for large enough frequencies they are predominantly generated in the perpendicular direction. Such change in longitudinal and transverse momentum sharing of created particles occurs accross the one-photon threshold.","PeriodicalId":7164,"journal":{"name":"Acta Physica Polonica A","volume":"39 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90679959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.12693/APhysPolA.143.S87
W. Price, M. Formánek, J. Rafelski
We study the effect of the limiting field strength of Born-Infeld electromagnetism on the dynamics of charged particle scattering. We formulate the Born-Infeld limiting field in an invariant manner, showing that it is the electric field-dominated eigenvalue `$a$' of the field tensor $F^{munu}$ which is limited rather than the individual field vectors. Heavy ion collisions in particular provide uniquely large values of the field invariants that appear in the BI action, amplifying nonlinear effects. Thus ``$a$'' is the dominant input into the force between heavy ions that we use to compute the scattering angle as a function of impact parameter. We evaluate the BI effects, showing relevance at small impact parameters and exhibiting their dependence on the value of the limiting field strength.
{"title":"Born-Infeld Nonlinear Electromagnetism in Relativistic Heavy Ion Collisions","authors":"W. Price, M. Formánek, J. Rafelski","doi":"10.12693/APhysPolA.143.S87","DOIUrl":"https://doi.org/10.12693/APhysPolA.143.S87","url":null,"abstract":"We study the effect of the limiting field strength of Born-Infeld electromagnetism on the dynamics of charged particle scattering. We formulate the Born-Infeld limiting field in an invariant manner, showing that it is the electric field-dominated eigenvalue `$a$' of the field tensor $F^{munu}$ which is limited rather than the individual field vectors. Heavy ion collisions in particular provide uniquely large values of the field invariants that appear in the BI action, amplifying nonlinear effects. Thus ``$a$'' is the dominant input into the force between heavy ions that we use to compute the scattering angle as a function of impact parameter. We evaluate the BI effects, showing relevance at small impact parameters and exhibiting their dependence on the value of the limiting field strength.","PeriodicalId":7164,"journal":{"name":"Acta Physica Polonica A","volume":"13 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73119517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.12693/aphyspola.143.s191
V. Cao Long, Dung Nguyen Trong
The paper studies the influence of several factors such as the number of atoms ( N ) , temperature ( T ) , and annealing time ( t ) on the characteristic quantities of structure, phase transition, and crystallization progress of bulk Au materials using so-called molecular dynamics simulation. The authors hope that obtained results would be very useful for near future experimental research with Au.
{"title":"Molecular Dynamics Approach to Processes in Bulk Au Materials","authors":"V. Cao Long, Dung Nguyen Trong","doi":"10.12693/aphyspola.143.s191","DOIUrl":"https://doi.org/10.12693/aphyspola.143.s191","url":null,"abstract":"The paper studies the influence of several factors such as the number of atoms ( N ) , temperature ( T ) , and annealing time ( t ) on the characteristic quantities of structure, phase transition, and crystallization progress of bulk Au materials using so-called molecular dynamics simulation. The authors hope that obtained results would be very useful for near future experimental research with Au.","PeriodicalId":7164,"journal":{"name":"Acta Physica Polonica A","volume":"26 2 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83777179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.12693/APhysPolA.143.S183
L. Turski
This paper outlines a variety of possible applications of the Vlasov equation and its generalization, i.e., the Klimontovich equation, in various areas of many-body physics. In particular, these equations are shown to be used in relativistic plasma physics, the theory of semi-classical Bloch electrons, and the metriplectic description of dissipative processes.
{"title":"Vlasov-Klimontovich Equation in Action","authors":"L. Turski","doi":"10.12693/APhysPolA.143.S183","DOIUrl":"https://doi.org/10.12693/APhysPolA.143.S183","url":null,"abstract":"This paper outlines a variety of possible applications of the Vlasov equation and its generalization, i.e., the Klimontovich equation, in various areas of many-body physics. In particular, these equations are shown to be used in relativistic plasma physics, the theory of semi-classical Bloch electrons, and the metriplectic description of dissipative processes.","PeriodicalId":7164,"journal":{"name":"Acta Physica Polonica A","volume":"127 4 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77440132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.12693/APhysPolA.143.S107
J. Przeszowski
Free electromagnetic fields, satisfying Maxwell's equations with no charges and electric currents, can be described by complex vector fields. In the standard formulation with fields sharply dependent on position and time, one obtains integrals that are mathematically ill-defined. This happens for the massless Pauli--Jordan function, which is used to describe the time evolution of fields and appears in the Poisson brackets for classical fields. This difficulty can be solved by introducing smeared fields as linear functionals with test functions. In this way, the massless Pauli--Jordan function becomes a~tempered distribution, allowing a mathematically rigorous analysis.
{"title":"Smeared Field Description of Free Electromagnetic Field","authors":"J. Przeszowski","doi":"10.12693/APhysPolA.143.S107","DOIUrl":"https://doi.org/10.12693/APhysPolA.143.S107","url":null,"abstract":"Free electromagnetic fields, satisfying Maxwell's equations with no charges and electric currents, can be described by complex vector fields. In the standard formulation with fields sharply dependent on position and time, one obtains integrals that are mathematically ill-defined. This happens for the massless Pauli--Jordan function, which is used to describe the time evolution of fields and appears in the Poisson brackets for classical fields. This difficulty can be solved by introducing smeared fields as linear functionals with test functions. In this way, the massless Pauli--Jordan function becomes a~tempered distribution, allowing a mathematically rigorous analysis.","PeriodicalId":7164,"journal":{"name":"Acta Physica Polonica A","volume":"50 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90479589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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