Pub Date : 2021-02-26DOI: 10.36227/TECHRXIV.14054051.V1
G. Xiao
A theory for analyzing the radiative and reactive energies for pulse radiators in free space is presented. With the proposed definition of reactive energies and radiative energies, power balance at arbitrarily chosen observation surfaces are established, which intuitively shows that the Poynting vector contains not only the power flux density associated with the radiative energies, but also the influence of the fluctuation of the reactive energies dragging by the sources. A new vector is defined for the radiative power flux density. The radiative energies passing through observation surfaces enclosing the radiator are accurately calculated. Numerical results verifies that the proposed radiative flux density is more proper for expressing the radiative power flux density than the Poynting vector.
{"title":"A Theory for Analysis of Pulse Electromagnetic Radiation","authors":"G. Xiao","doi":"10.36227/TECHRXIV.14054051.V1","DOIUrl":"https://doi.org/10.36227/TECHRXIV.14054051.V1","url":null,"abstract":"A theory for analyzing the\u0000radiative and reactive energies for pulse radiators in free space is presented.\u0000With the proposed definition of reactive energies and radiative energies, power\u0000balance at arbitrarily chosen observation surfaces are established, which\u0000intuitively shows that the Poynting vector contains not only the power flux\u0000density associated with the radiative energies, but also the influence of the\u0000fluctuation of the reactive energies dragging by the sources. A new vector is\u0000defined for the radiative power flux density. The radiative energies passing\u0000through observation surfaces enclosing the radiator are accurately calculated.\u0000Numerical results verifies that the proposed radiative flux density is more\u0000proper for expressing the radiative power flux density than the Poynting vector.","PeriodicalId":331413,"journal":{"name":"arXiv: Classical Physics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122594849","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}
Pub Date : 2020-11-24DOI: 10.2140/MEMOCS.2021.9.77
M. Olive, N. Auffray
The piezoelectricity law is a constitutive model that describes how mechanical and electric fields are coupled within a material. In its linear formulation this law comprises three constitutive tensors of increasing order: the second order permittivity tensor S, the third order piezoelectricity tensor P and the fourth-order elasticity tensor C. In a first part of the paper, the symmetry classes of the piezoelectricity tensor alone are investigated. Using a new approach based on the use of the so-called clips operations, we establish the 16 symmetry classes of this tensor and provide their associated normal forms. Second order orthogonal transformations (plane symmetries and π-angle rotations) are then used to characterize and classify directly 11 out of the 16 symmetry classes of the piezoelectricity tensor. An additional step to distinguish the remaining classes is proposed
{"title":"Symmetry classes in piezoelectricity from second-order symmetries","authors":"M. Olive, N. Auffray","doi":"10.2140/MEMOCS.2021.9.77","DOIUrl":"https://doi.org/10.2140/MEMOCS.2021.9.77","url":null,"abstract":"The piezoelectricity law is a constitutive model that describes how mechanical and \u0000electric fields are coupled within a material. In its linear formulation this law comprises three \u0000constitutive tensors of increasing order: the second order permittivity tensor S, the third order \u0000piezoelectricity tensor P and the fourth-order elasticity tensor C. In a first part of the paper, \u0000the symmetry classes of the piezoelectricity tensor alone are investigated. Using a new approach \u0000based on the use of the so-called clips operations, we establish the 16 symmetry classes of this \u0000tensor and provide their associated normal forms. Second order orthogonal transformations \u0000(plane symmetries and π-angle rotations) are then used to characterize and classify directly 11 \u0000out of the 16 symmetry classes of the piezoelectricity tensor. An additional step to distinguish \u0000the remaining classes is proposed","PeriodicalId":331413,"journal":{"name":"arXiv: Classical Physics","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129437118","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}
In our prior studies we synthesized special circuits possessing evolution matrices that involve nontrivial Jordan blocks and the corresponding degenerate eigenfrequencies. The degeneracy of this type is sometimes referred to as exceptional point of degeneracy (EPD). The simplest of these circuits are composed just of two LC-loops coupled by a gyrator and they are of our primary interest here. These simple circuits when near an EPD state can be used for enhanced sensitivity applications. With that in mind we develop here a comprehensive perturbation theory for these simple circuits near an EPD as well way to assure their stable operation. As to broader problem of numerical treatment of Jordan blocks and their perturbation we propose a few approaches allowing to detect the proximity to Jordan blocks.
{"title":"Perturbations of circuit evolution matrices with Jordan blocks","authors":"A. Figotin","doi":"10.1063/5.0039970","DOIUrl":"https://doi.org/10.1063/5.0039970","url":null,"abstract":"In our prior studies we synthesized special circuits possessing evolution matrices that involve nontrivial Jordan blocks and the corresponding degenerate eigenfrequencies. The degeneracy of this type is sometimes referred to as exceptional point of degeneracy (EPD). The simplest of these circuits are composed just of two LC-loops coupled by a gyrator and they are of our primary interest here. These simple circuits when near an EPD state can be used for enhanced sensitivity applications. With that in mind we develop here a comprehensive perturbation theory for these simple circuits near an EPD as well way to assure their stable operation. As to broader problem of numerical treatment of Jordan blocks and their perturbation we propose a few approaches allowing to detect the proximity to Jordan blocks.","PeriodicalId":331413,"journal":{"name":"arXiv: Classical Physics","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124586606","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}
Pub Date : 2020-10-28DOI: 10.1103/PHYSREVAPPLIED.15.034041
M. Sidorenko, O. Sergaeva, Z. Sadrieva, C. Roques-Carmes, P. Muraev, D. Maksimov, A. Bogdanov
Being a general wave phenomenon, bound states in the continuum (BICs) appear in acoustic, hydrodynamic, and photonic systems of various dimensionalities. Here, we report the first experimental observation of an accidental electromagnetic BIC in a one-dimensional periodic chain of coaxial ceramic disks. We show that the accidental BIC manifests itself as a narrow peak in the transmission spectra of the chain placed between two loop antennas. We demonstrate a linear growth of the radiative quality factor of the BICs with the number of disks that is well-described with a tight-binding model. We estimate the number of the disks when the radiation losses become negligible in comparison to material absorption and, therefore, the chain can be considered practically as infinite. The presented analysis is supported by near-field measurements of the BIC profile. The obtained results provide useful guidelines for practical implementations of structures with BICs opening new horizons for the development of radio-frequency and optical metadevices.
{"title":"Observation of an Accidental Bound State in the Continuum in a Chain of Dielectric Disks","authors":"M. Sidorenko, O. Sergaeva, Z. Sadrieva, C. Roques-Carmes, P. Muraev, D. Maksimov, A. Bogdanov","doi":"10.1103/PHYSREVAPPLIED.15.034041","DOIUrl":"https://doi.org/10.1103/PHYSREVAPPLIED.15.034041","url":null,"abstract":"Being a general wave phenomenon, bound states in the continuum (BICs) appear in acoustic, hydrodynamic, and photonic systems of various dimensionalities. Here, we report the first experimental observation of an accidental electromagnetic BIC in a one-dimensional periodic chain of coaxial ceramic disks. We show that the accidental BIC manifests itself as a narrow peak in the transmission spectra of the chain placed between two loop antennas. We demonstrate a linear growth of the radiative quality factor of the BICs with the number of disks that is well-described with a tight-binding model. We estimate the number of the disks when the radiation losses become negligible in comparison to material absorption and, therefore, the chain can be considered practically as infinite. The presented analysis is supported by near-field measurements of the BIC profile. The obtained results provide useful guidelines for practical implementations of structures with BICs opening new horizons for the development of radio-frequency and optical metadevices.","PeriodicalId":331413,"journal":{"name":"arXiv: Classical Physics","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121608222","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}
Recent experiments conducted in the International Space Station highlight the apparent periodicity of leaf oscillations and other biological phenomena associated with rhythmic variations of lunisolar forces. These events are similar to those occurring on Earth, but with greater effects over a shorter period of time. Among the possible disturbances, other than forced or self-existing oscillations, parametric resonances appear caused by a small periodic term; such is the case of fluids subjected to small periodic variations in gravitational forces in microscopic or mesoscopic plant channels filled with sap and air-vapor. The interface instabilities verify a Mathieu's second order differential equation resulting from a Rayleigh-Taylor stability model. These instabilities appear during the Moon's rotation around the Earth and during the revolution of the International Space Station. They create impulses of pressure and sap movements in the network of roots, stems and leaves. The model can explain the effects of the lunar tide on plant growth. The eccentricity of the lunar orbit around the Earth creates an important difference between the apogee and perigee of the Moon's trajectory and therefore the tidal effects can depend on the distance between the Moon and the Earth.
{"title":"Influence of lunisolar tides on plants. Parametric resonance induced by periodic variations of gravity","authors":"H. Gouin","doi":"10.1063/5.0023717","DOIUrl":"https://doi.org/10.1063/5.0023717","url":null,"abstract":"Recent experiments conducted in the International Space Station highlight the apparent periodicity of leaf oscillations and other biological phenomena associated with rhythmic variations of lunisolar forces. These events are similar to those occurring on Earth, but with greater effects over a shorter period of time. Among the possible disturbances, other than forced or self-existing oscillations, parametric resonances appear caused by a small periodic term; such is the case of fluids subjected to small periodic variations in gravitational forces in microscopic or mesoscopic plant channels filled with sap and air-vapor. The interface instabilities verify a Mathieu's second order differential equation resulting from a Rayleigh-Taylor stability model. These instabilities appear during the Moon's rotation around the Earth and during the revolution of the International Space Station. They create impulses of pressure and sap movements in the network of roots, stems and leaves. The model can explain the effects of the lunar tide on plant growth. The eccentricity of the lunar orbit around the Earth creates an important difference between the apogee and perigee of the Moon's trajectory and therefore the tidal effects can depend on the distance between the Moon and the Earth.","PeriodicalId":331413,"journal":{"name":"arXiv: Classical Physics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129852460","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}
You have a rocket in a high circular orbit around a massive central body (a planet, or the Sun) and wish to escape with the fastest possible speed at infinity for a given amount of fuel.
{"title":"High-speed escape from a circular orbit","authors":"Philip R Blanco, C. Mungan","doi":"10.1119/10.0001956","DOIUrl":"https://doi.org/10.1119/10.0001956","url":null,"abstract":"You have a rocket in a high circular orbit around a massive central body (a planet, or the Sun) and wish to escape with the fastest possible speed at infinity for a given amount of fuel.","PeriodicalId":331413,"journal":{"name":"arXiv: Classical Physics","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121043458","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}
It is believed that thermodynamic laws are associated with random processes occurring in the system and, therefore, deterministic mechanical systems cannot be described within the framework of the thermodynamic approach. In this paper, we show that thermodynamics (or, more precisely, a thermodynamically-like description) can be constructed even for deterministic Hamiltonian systems, for example, systems with only one degree of freedom. We show that for such systems it is possible to introduce analogs of thermal energy, temperature, entropy, Helmholtz free energy, etc., which are related to each other by the usual thermodynamic relations. For the considered Hamiltonian systems, the first and second laws of thermodynamics are rigorously derived, which have the same form as in ordinary (molecular) thermodynamics. It is shown that for Hamiltonian systems it is possible to introduce the concepts of a thermodynamic state, a thermodynamic process, and thermodynamic cycles, in particular, the Carnot cycle, which are described by the same relations as their usual thermodynamic analogs.
{"title":"Hamiltonian Thermodynamics","authors":"S. Rashkovskiy","doi":"10.20537/nd200403","DOIUrl":"https://doi.org/10.20537/nd200403","url":null,"abstract":"It is believed that thermodynamic laws are associated with random processes occurring in the system and, therefore, deterministic mechanical systems cannot be described within the framework of the thermodynamic approach. In this paper, we show that thermodynamics (or, more precisely, a thermodynamically-like description) can be constructed even for deterministic Hamiltonian systems, for example, systems with only one degree of freedom. We show that for such systems it is possible to introduce analogs of thermal energy, temperature, entropy, Helmholtz free energy, etc., which are related to each other by the usual thermodynamic relations. For the considered Hamiltonian systems, the first and second laws of thermodynamics are rigorously derived, which have the same form as in ordinary (molecular) thermodynamics. It is shown that for Hamiltonian systems it is possible to introduce the concepts of a thermodynamic state, a thermodynamic process, and thermodynamic cycles, in particular, the Carnot cycle, which are described by the same relations as their usual thermodynamic analogs.","PeriodicalId":331413,"journal":{"name":"arXiv: Classical Physics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130687443","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}
Pub Date : 2020-08-17DOI: 10.1103/physrevb.102.174312
I. Brouzos, I. Kiorpelidis, F. Diakonos, G. Theocharis
We show that it is possible to successfully, rapidly and robustly transfer a topological vibrational edge mode across a time-varying mechanical chain. The stiffness values of the springs of the chain are arranged in an alternating staggered way, such that we obtain a mechanical analog of the quantum Su-Schrieffer-Heeger model which exhibits a non trivial topological phase. Using optimal control methods, we are able to design control schemes for driving the stiffness parameters, such that the transfer is done with high fidelity, speed and robustness against disorder as well as energy amplification of the target edge mode.
{"title":"Fast, robust, and amplified transfer of topological edge modes on a time-varying mechanical chain","authors":"I. Brouzos, I. Kiorpelidis, F. Diakonos, G. Theocharis","doi":"10.1103/physrevb.102.174312","DOIUrl":"https://doi.org/10.1103/physrevb.102.174312","url":null,"abstract":"We show that it is possible to successfully, rapidly and robustly transfer a topological vibrational edge mode across a time-varying mechanical chain. The stiffness values of the springs of the chain are arranged in an alternating staggered way, such that we obtain a mechanical analog of the quantum Su-Schrieffer-Heeger model which exhibits a non trivial topological phase. Using optimal control methods, we are able to design control schemes for driving the stiffness parameters, such that the transfer is done with high fidelity, speed and robustness against disorder as well as energy amplification of the target edge mode.","PeriodicalId":331413,"journal":{"name":"arXiv: Classical Physics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115742576","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}
Pub Date : 2020-08-17DOI: 10.1103/PHYSREVAPPLIED.15.024034
Neng Wang, Ruo-Yang Zhang, C. T. Chan
We show that long-range and robust acoustic pulling can be achieved by using a pair of one-way chiral surface waves supported on the interface between two phononic crystals composed of spinning cylinders with equal but opposite spinning velocities embedded in water. When the chiral surface mode with a relative small Bloch wave vector is excited, the particle located in the interface waveguide will scatter the excited surface mode to another chiral surface mode with a greater Bloch wave vector, resulting in an acoustic pulling force, irrespective of the size and material of the particle. Thanks to the backscattering immunity of the chiral surface waves against local disorders, the particle can be pulled following a flexible trajectory as determined by the shape of the interface. As such, this new acoustic pulling scheme overcomes some of the limitations of the traditional acoustic pulling using structured beams, such as short pulling distances, straight-line type pulling and strong dependence on the scattering properties of the particle. Our work may also inspire the application of topological acoustics to acoustic manipulations.
{"title":"Robust Acoustic Pulling Using Chiral Surface Waves","authors":"Neng Wang, Ruo-Yang Zhang, C. T. Chan","doi":"10.1103/PHYSREVAPPLIED.15.024034","DOIUrl":"https://doi.org/10.1103/PHYSREVAPPLIED.15.024034","url":null,"abstract":"We show that long-range and robust acoustic pulling can be achieved by using a pair of one-way chiral surface waves supported on the interface between two phononic crystals composed of spinning cylinders with equal but opposite spinning velocities embedded in water. When the chiral surface mode with a relative small Bloch wave vector is excited, the particle located in the interface waveguide will scatter the excited surface mode to another chiral surface mode with a greater Bloch wave vector, resulting in an acoustic pulling force, irrespective of the size and material of the particle. Thanks to the backscattering immunity of the chiral surface waves against local disorders, the particle can be pulled following a flexible trajectory as determined by the shape of the interface. As such, this new acoustic pulling scheme overcomes some of the limitations of the traditional acoustic pulling using structured beams, such as short pulling distances, straight-line type pulling and strong dependence on the scattering properties of the particle. Our work may also inspire the application of topological acoustics to acoustic manipulations.","PeriodicalId":331413,"journal":{"name":"arXiv: Classical Physics","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126167039","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}
We consider the dynamics of a classical charge in flat spacetime of six dimensions. The mass shell relation of a free charge admits nonlinear oscillations. Having analyzed the problem of on eigenvalues and eigenvectors of Faraday tensor, we establish the algebraic structure of electromagnetic field in 6D. We elaborate the classification scheme based on three field's invariants. Using the basic algebraic properties of the electromagnetic field tensor we analyze the motion of a charge in constant electromagnetic field. Its world line is a combination of hyperbolic and circular orbits which lie in three mutually orthogonal sheets of two dimensions. Within the braneworld scenario, we project the theory on the de Sitter space of four dimensions. Actually, as it turns out, spins of elementary particles themselves are manifestations of extra dimensions.
{"title":"Electrodynamics in flat spacetime of six dimensions","authors":"Y. Yaremko","doi":"10.1063/5.0023477","DOIUrl":"https://doi.org/10.1063/5.0023477","url":null,"abstract":"We consider the dynamics of a classical charge in flat spacetime of six dimensions. The mass shell relation of a free charge admits nonlinear oscillations. Having analyzed the problem of on eigenvalues and eigenvectors of Faraday tensor, we establish the algebraic structure of electromagnetic field in 6D. We elaborate the classification scheme based on three field's invariants. Using the basic algebraic properties of the electromagnetic field tensor we analyze the motion of a charge in constant electromagnetic field. Its world line is a combination of hyperbolic and circular orbits which lie in three mutually orthogonal sheets of two dimensions. Within the braneworld scenario, we project the theory on the de Sitter space of four dimensions. Actually, as it turns out, spins of elementary particles themselves are manifestations of extra dimensions.","PeriodicalId":331413,"journal":{"name":"arXiv: Classical Physics","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123819212","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}
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