In this short review paper we essentially focus on the high energy spectroscopies which involve second order quantum processes, i.e., resonance photoemission, Auger and X-ray emission spectroscopies, denoted respectively by RXPS, AES and XES. First, we summarize the main 3P-RXPS and AES results obtained in Cu and Ni metals; especially we recall that the satellite near the 3P-threshold in the spectra, which arises from a d-hole pair bound state, needs a careful treatment of the electron-electron correlation. Then we analyze the RXPS spectra in a few Ce compounds (Ce02, Ce20a and CeFa) involving 3d or 4d core levels and we interpret the spectra consistently with the other spectroscopies, such as core XPS and XAS which are first order quantum processes. Finally within the same one-impurity model and basically with the same sets of parameters, we review a theory for the Ce 5p-+ 3d XES, as well as for the corresponding RXES, where (1) the incident X-ray is tuned to resonate with the 3d -+4! transition and (2) the X-ray emission due to the 5p-+3d transition is actually observed. The paper ends with a general discussion.
在这篇简短的综述文章中，我们主要关注涉及二阶量子过程的高能光谱，即共振光发射光谱、俄歇光谱和x射线发射光谱，分别用RXPS、AES和XES表示。首先，总结了Cu和Ni金属中获得的主要3P-RXPS和AES结果;特别是我们记得，在光谱中靠近3p阈值的卫星，它是由d空穴对束缚态产生的，需要仔细处理电子-电子相关。在此基础上，对Ce02、Ce20a和CeFa等铈化合物的三维或四维核能级的RXPS光谱进行了分析，并与核心XPS和XAS等一阶量子过程的光谱进行了一致的解释。最后，在相同的单杂质模型和基本相同的参数集下，我们回顾了Ce 5p-+ 3d x射线的理论，以及相应的rx射线，其中(1)入射x射线被调谐为与3d -+4!(2)实际观测到5p-+三维跃迁引起的x射线辐射。论文最后作了一般性讨论。
{"title":"Electron-Electron Correlation, Resonant Photoemission and X-Ray Emission Spectra","authors":"J. Parlebas, A. Kotani, Satoshi Tanaka","doi":"10.1143/PTPS.101.271","DOIUrl":"https://doi.org/10.1143/PTPS.101.271","url":null,"abstract":"In this short review paper we essentially focus on the high energy spectroscopies which involve second order quantum processes, i.e., resonance photoemission, Auger and X-ray emission spectroscopies, denoted respectively by RXPS, AES and XES. First, we summarize the main 3P-RXPS and AES results obtained in Cu and Ni metals; especially we recall that the satellite near the 3P-threshold in the spectra, which arises from a d-hole pair bound state, needs a careful treatment of the electron-electron correlation. Then we analyze the RXPS spectra in a few Ce compounds (Ce02, Ce20a and CeFa) involving 3d or 4d core levels and we interpret the spectra consistently with the other spectroscopies, such as core XPS and XAS which are first order quantum processes. Finally within the same one-impurity model and basically with the same sets of parameters, we review a theory for the Ce 5p-+ 3d XES, as well as for the corresponding RXES, where (1) the incident X-ray is tuned to resonate with the 3d -+4! transition and (2) the X-ray emission due to the 5p-+3d transition is actually observed. The paper ends with a general discussion.","PeriodicalId":20614,"journal":{"name":"Progress of Theoretical Physics Supplement","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64704281","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 the present paper we study scaling field theories related to the class of exactly solvable noncritical models of statistical mechanics which are known as RSOS (restricted solid-on-solid) or IRF (interaction round a face) models. These models are related to simple Lie algebras and they generalize the integrable version of RSOS model proposed by Andrews, Baxter and Forrester. 1> The models related to gl(n) were found by Jimbo, Miwa and Okado,2> the models related to other classical Lie algebras were obtained by the same authors in Ref. 3) and by Pasquier in Ref. 4) for Dn-case with a special coupling constant. Critical properties of JMO model were found in Ref. 5) where the authors obtain the explicit formulas for magnetization in the model and compute its critical behavior. It was established there that the critical behavior of these models was described by coset conformal field theories. 6>.7> Therefore it is natural to expect that corre sponding scaling field theories will be integrable perturbations of these conformal field theories. s> In this paper we describe the thermodynamics of the noncritical magnetic chain. Then we find the ground state, excitations over the ground state and the scattering amplitudes of excitations. By getting the scaling limit over the ground state of the model we compute the central charges of corresponding field theories, the dimensions of perturbations, the spectrum and scattering amplitudes of excitations. Under certain assumptions we generalize these results for any Lie algebra of A-D-E type. In certain simplest cases this gives known S-matrices like Es, E1, Es scalar S-matrices.9> In certain other models matrix elements of the S-matrix are given by Pasquier's solutions 4> of the Yang-Baxter equation. We do not discuss here the relation of RSOS models to integrable models of vertex type. 23>' 25> Partially the relation was explained in Refs. 4) and 26). The relation between the spectrum of row-to-row transfer matrices in RSOS and in vertex models will be given in a separate publication. For some of the scaling models the same answer was obtained by Bernard and
{"title":"Scattering Amplitudes in Offcritical Models and RSOS Integrable Models","authors":"V. Bazhanov, N. Reshetikhin","doi":"10.1143/PTPS.102.301","DOIUrl":"https://doi.org/10.1143/PTPS.102.301","url":null,"abstract":"In the present paper we study scaling field theories related to the class of exactly solvable noncritical models of statistical mechanics which are known as RSOS (restricted solid-on-solid) or IRF (interaction round a face) models. These models are related to simple Lie algebras and they generalize the integrable version of RSOS model proposed by Andrews, Baxter and Forrester. 1> The models related to gl(n) were found by Jimbo, Miwa and Okado,2> the models related to other classical Lie algebras were obtained by the same authors in Ref. 3) and by Pasquier in Ref. 4) for Dn-case with a special coupling constant. Critical properties of JMO model were found in Ref. 5) where the authors obtain the explicit formulas for magnetization in the model and compute its critical behavior. It was established there that the critical behavior of these models was described by coset conformal field theories. 6>.7> Therefore it is natural to expect that corre sponding scaling field theories will be integrable perturbations of these conformal field theories. s> In this paper we describe the thermodynamics of the noncritical magnetic chain. Then we find the ground state, excitations over the ground state and the scattering amplitudes of excitations. By getting the scaling limit over the ground state of the model we compute the central charges of corresponding field theories, the dimensions of perturbations, the spectrum and scattering amplitudes of excitations. Under certain assumptions we generalize these results for any Lie algebra of A-D-E type. In certain simplest cases this gives known S-matrices like Es, E1, Es scalar S-matrices.9> In certain other models matrix elements of the S-matrix are given by Pasquier's solutions 4> of the Yang-Baxter equation. We do not discuss here the relation of RSOS models to integrable models of vertex type. 23>' 25> Partially the relation was explained in Refs. 4) and 26). The relation between the spectrum of row-to-row transfer matrices in RSOS and in vertex models will be given in a separate publication. For some of the scaling models the same answer was obtained by Bernard and","PeriodicalId":20614,"journal":{"name":"Progress of Theoretical Physics Supplement","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1143/PTPS.102.301","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64706806","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}
heory of the resonant 3d→2p X-ray emission spectroscopy (3d→2p RXES) for insulating La compounds is presented; the incident photon is tuned to resonate with the 2p→5d or continuum band (6s, 6d, ..., es, ed) transition and the X-ray emission due to the 3d→2p transition is observed. The spectra are calculated by using the impurity Anderson model and by applying the formula of a coherent second order optical process
{"title":"Theory of Post-Collision-Interaction Effect in Resonant XES of La Compounds","authors":"A. Mori, Y. Kayanuma, A. Kotani","doi":"10.1143/PTPS.106.75","DOIUrl":"https://doi.org/10.1143/PTPS.106.75","url":null,"abstract":"heory of the resonant 3d→2p X-ray emission spectroscopy (3d→2p RXES) for insulating La compounds is presented; the incident photon is tuned to resonate with the 2p→5d or continuum band (6s, 6d, ..., es, ed) transition and the X-ray emission due to the 3d→2p transition is observed. The spectra are calculated by using the impurity Anderson model and by applying the formula of a coherent second order optical process","PeriodicalId":20614,"journal":{"name":"Progress of Theoretical Physics Supplement","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64714782","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 work on the Hubbard model is reviewed. What occur in the Mott-transition region are the formation of the Gutzwiller heavy-electron band within the Mott-Hubbard gap, and magnetic or superconducting instability of heavy-electron liquids by exchange interac tions. Application to high-temperature superconductivity in the cuprate oxides is presented ..
{"title":"Heavy Electrons in the Mott-Transition Region","authors":"F. J. Ohkawa","doi":"10.1143/PTPS.106.95","DOIUrl":"https://doi.org/10.1143/PTPS.106.95","url":null,"abstract":"Recent work on the Hubbard model is reviewed. What occur in the Mott-transition region are the formation of the Gutzwiller heavy-electron band within the Mott-Hubbard gap, and magnetic or superconducting instability of heavy-electron liquids by exchange interac tions. Application to high-temperature superconductivity in the cuprate oxides is presented ..","PeriodicalId":20614,"journal":{"name":"Progress of Theoretical Physics Supplement","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64714884","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 study quantum classical correspondence in nonintegrable systems with a continuous parameter. In a stadium billiard with an aspect ratio as a parameter, we show that the slope of the parametric motion of eigenvalues is mainly due to the first derivative of periodic orbit length with respect to the parameter. We also present a viewpoint for scarred wavefunctions in a continuous change of the systems. Since the discovery of scars 1 > in a stadium billiard/> a number of authors have studied properties of scars numerically in various systems.3> Several theoretical studies4 >,s> have tried to explain the extra accumulation of the wave function on an unstable periodic orbit (PO). Although these works seemed to confirm the existence of scars both numerically and theoretically, the semiclassical theory for individual eigenstates in nonintegrable systems has not been given yet. The difficulty in the investigation for the individual eigenstates is due to the strong interaction with other states. The origin of the repulsive interaction has been studied by many authors, and was related to chaotic behavior in the classical motion. 6> When we change a parameter in the Hamiltonian, it is well known that eigenvalues of nonintegrable systems show a number of avoided crossings due to the interaction. The definite representation for the interaction was given by the level dynamics,?> and the motion of levels was shown to be described by a classical Hamiltonian with complete integrability. The curvature of levels, i.e. the second derivative of eigenvalues with respect to the parameter, have been introduced to characterize the parametric property of eigenvalues, and the expressions for the large curvature tail of the distribution have been derived. 8> The universal behavior in large curvatures is checked in various systems by numerical calculations. 9 > On the other hand, the nonuniversal behavior of small curvatures was discovered numerically. 10> Zakrzewski and Delande11> suggest that the discrepancy in small curvatures can be used to classify the degree of scarring in different systems. In this paper, we consider the relation between classical PO's and the parametric motion of eigenvalues of the stadium billiard with an aspect ratio as a parameter. In § 2, we study properties of PO's when we change the parameter continuously. We concentrate on the continuity of the PO's and calculate the first derivative of the
{"title":"Quantum Classical Correspondence in Nonintegrable Systems with Continuous Parameter","authors":"T. Takami","doi":"10.1143/PTPS.116.303","DOIUrl":"https://doi.org/10.1143/PTPS.116.303","url":null,"abstract":"We study quantum classical correspondence in nonintegrable systems with a continuous parameter. In a stadium billiard with an aspect ratio as a parameter, we show that the slope of the parametric motion of eigenvalues is mainly due to the first derivative of periodic orbit length with respect to the parameter. We also present a viewpoint for scarred wavefunctions in a continuous change of the systems. Since the discovery of scars 1 > in a stadium billiard/> a number of authors have studied properties of scars numerically in various systems.3> Several theoretical studies4 >,s> have tried to explain the extra accumulation of the wave function on an unstable periodic orbit (PO). Although these works seemed to confirm the existence of scars both numerically and theoretically, the semiclassical theory for individual eigenstates in nonintegrable systems has not been given yet. The difficulty in the investigation for the individual eigenstates is due to the strong interaction with other states. The origin of the repulsive interaction has been studied by many authors, and was related to chaotic behavior in the classical motion. 6> When we change a parameter in the Hamiltonian, it is well known that eigenvalues of nonintegrable systems show a number of avoided crossings due to the interaction. The definite representation for the interaction was given by the level dynamics,?> and the motion of levels was shown to be described by a classical Hamiltonian with complete integrability. The curvature of levels, i.e. the second derivative of eigenvalues with respect to the parameter, have been introduced to characterize the parametric property of eigenvalues, and the expressions for the large curvature tail of the distribution have been derived. 8> The universal behavior in large curvatures is checked in various systems by numerical calculations. 9 > On the other hand, the nonuniversal behavior of small curvatures was discovered numerically. 10> Zakrzewski and Delande11> suggest that the discrepancy in small curvatures can be used to classify the degree of scarring in different systems. In this paper, we consider the relation between classical PO's and the parametric motion of eigenvalues of the stadium billiard with an aspect ratio as a parameter. In § 2, we study properties of PO's when we change the parameter continuously. We concentrate on the continuity of the PO's and calculate the first derivative of the","PeriodicalId":20614,"journal":{"name":"Progress of Theoretical Physics Supplement","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64726385","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 introduce momentum-dependent scalar and vector fields into the Lorentz covariant RBUU-approach in line with the empirical proton-nucleus relativistic optical potential. Within this extended RBUU-approach we perform numerical simulations for heavy-ion collisions and calculate the transverse flow of nucleons as well as subthreshold production of K+ mesons. By means of these observables we discuss the particular role of the momentum dependent forces and their implications on the nuclear equation of state. We find that only a momentum-dependent parameter-set can explain the experimental data on the transverse flow from 150-1000 MeV /u and the differential K+-production cross sections at 1 GeV /u at the same time. The main aim of the high energy heavy-ion physics is to determine the equation of state (EOS) of nuclear matter under extreme conditions far from the ground state. Any conclusion on the properties of hot and dense matter must rely on the comparison of the experimental data with theoretical predictions based on nonequilibrium models. Among these, the BUU-approach1>'2> is a very successful approach in describing the time-dependent evolution of the complex system. As a genuine feature of transport theories it has two important ingredients: the mean-fields or self-energies for nucleons and an in-medium nucleon-nucleon cross-section that accounts for the elastic and inelastic channels. By varying the mean-fields which reflect a certain EOS and comparing the theoretical calculations with the experimental data, one expects to be able to determine the nuclear EOS. Within the framework of BUD-simulations we have succeeded to predict/repro duce particle production data in heavy-ion collisions and to clarify their reaction processes.3> In spite of this success the nuclear EOS has not been determined com pletely, yet. The mean fields cannot be uniquely determined by the equation of state alone, and, in addition, it is not always possible to extract the nuclear EOS from the results of the BUU calculations without ambiguities for other model inputs. The most important model inputs besides the nuclear incompressibility are the momentum-dependence4> and the Lorentz covariance5> of the mean-fields in the high energy region. Thus we introduce an explicit momentum-dependence of the mean
{"title":"High Energy Heavy-Ion Collisions in a RBUU-Approach with Momentum-Dependent Mean-Fields","authors":"T. Maruyama, W. Cassing, U. Mosel, S. Teis","doi":"10.1143/PTPS.120.283","DOIUrl":"https://doi.org/10.1143/PTPS.120.283","url":null,"abstract":"We introduce momentum-dependent scalar and vector fields into the Lorentz covariant RBUU-approach in line with the empirical proton-nucleus relativistic optical potential. Within this extended RBUU-approach we perform numerical simulations for heavy-ion collisions and calculate the transverse flow of nucleons as well as subthreshold production of K+ mesons. By means of these observables we discuss the particular role of the momentum dependent forces and their implications on the nuclear equation of state. We find that only a momentum-dependent parameter-set can explain the experimental data on the transverse flow from 150-1000 MeV /u and the differential K+-production cross sections at 1 GeV /u at the same time. The main aim of the high energy heavy-ion physics is to determine the equation of state (EOS) of nuclear matter under extreme conditions far from the ground state. Any conclusion on the properties of hot and dense matter must rely on the comparison of the experimental data with theoretical predictions based on nonequilibrium models. Among these, the BUU-approach1>'2> is a very successful approach in describing the time-dependent evolution of the complex system. As a genuine feature of transport theories it has two important ingredients: the mean-fields or self-energies for nucleons and an in-medium nucleon-nucleon cross-section that accounts for the elastic and inelastic channels. By varying the mean-fields which reflect a certain EOS and comparing the theoretical calculations with the experimental data, one expects to be able to determine the nuclear EOS. Within the framework of BUD-simulations we have succeeded to predict/repro duce particle production data in heavy-ion collisions and to clarify their reaction processes.3> In spite of this success the nuclear EOS has not been determined com pletely, yet. The mean fields cannot be uniquely determined by the equation of state alone, and, in addition, it is not always possible to extract the nuclear EOS from the results of the BUU calculations without ambiguities for other model inputs. The most important model inputs besides the nuclear incompressibility are the momentum-dependence4> and the Lorentz covariance5> of the mean-fields in the high energy region. Thus we introduce an explicit momentum-dependence of the mean","PeriodicalId":20614,"journal":{"name":"Progress of Theoretical Physics Supplement","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64732033","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}
P. Lunkenheimer, A. Pimenov, M. Dressel, B. Schiener, U. Schneider, A. Loidl
{"title":"Broadband Dielectric Spectroscopy on Glass Forming Liquids","authors":"P. Lunkenheimer, A. Pimenov, M. Dressel, B. Schiener, U. Schneider, A. Loidl","doi":"10.1143/PTPS.126.123","DOIUrl":"https://doi.org/10.1143/PTPS.126.123","url":null,"abstract":"","PeriodicalId":20614,"journal":{"name":"Progress of Theoretical Physics Supplement","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64740198","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}
The glass-transition, crystallization and melting in GexSel-x (0 $ x $ 0.33) have been studied by Raman scattering. Raman spectra exhibit some anomalous changes at the glass transition. On the basis of these anomalous features which relate to the structural changes, we investigate a medium range structure in glassy and liquid GexSel-x· In the Ge compo sition range of 0.04 < x < 0.18, both GeSe2 and Se crystals are much more difficult to be obtained than in the other Ge composition.
用拉曼散射研究了GexSel-x (0 $ x $ 0.33)的玻璃化转变、结晶和熔化过程。拉曼光谱在玻璃化转变中表现出一些反常的变化。在这些与结构变化有关的异常特征的基础上，我们研究了玻璃态和液态gessel -x·的中范围结构。在0.04 < x < 0.18的Ge组成范围内，GeSe2和Se晶体比其他Ge组成更难获得。
{"title":"Structural Changes at Glass-Transition in GexSe1−x Studied by Raman Scattering","authors":"Yong Wang, O. Matsuda, Koichi Inoue, K. Murase","doi":"10.1143/PTPS.126.191","DOIUrl":"https://doi.org/10.1143/PTPS.126.191","url":null,"abstract":"The glass-transition, crystallization and melting in GexSel-x (0 $ x $ 0.33) have been studied by Raman scattering. Raman spectra exhibit some anomalous changes at the glass transition. On the basis of these anomalous features which relate to the structural changes, we investigate a medium range structure in glassy and liquid GexSel-x· In the Ge compo sition range of 0.04 < x < 0.18, both GeSe2 and Se crystals are much more difficult to be obtained than in the other Ge composition.","PeriodicalId":20614,"journal":{"name":"Progress of Theoretical Physics Supplement","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64740453","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":"Broadband Light Scattering from Glass-Forming Propylene Glycol","authors":"A. Yoshihara, H. Sato, S. Kojima","doi":"10.1143/PTPS.126.423","DOIUrl":"https://doi.org/10.1143/PTPS.126.423","url":null,"abstract":"","PeriodicalId":20614,"journal":{"name":"Progress of Theoretical Physics Supplement","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64742940","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}
Glasses and amorphous materials show, coexisting with the sound waves, a variety of low energy excitations: tunneling, quasi-localized vibrations and relaxations. The latter two are observed well into the liquid state. Using molecular dynamics both were shown to be centered, at low temperatures, typically on more than ten atoms or molecular units, which form chainlike structures. With increasing frequency the interaction of the quasi-localized modes with the sound waves and with each other increases, they de-localize. However, even at the so-called boson peak frequency, where the sound waves become over-damped due to the interaction, the vibrations can be decomposed into local and extended modes. Closely correlated with t.he local vibrations are the local relaxations, which can be envisaged as collective jumps of groups of atoms. With rising temperature both the total jump length and the number of atoms participating increases. In the melt when single jumps are no longer resolved one still observes a collective motion of chains of atoms.
{"title":"Low Energy Excitations in Glasses and Melts","authors":"H. Schober, C. Gaukel, C. Oligschleger","doi":"10.1143/PTPS.126.67","DOIUrl":"https://doi.org/10.1143/PTPS.126.67","url":null,"abstract":"Glasses and amorphous materials show, coexisting with the sound waves, a variety of low energy excitations: tunneling, quasi-localized vibrations and relaxations. The latter two are observed well into the liquid state. Using molecular dynamics both were shown to be centered, at low temperatures, typically on more than ten atoms or molecular units, which form chainlike structures. With increasing frequency the interaction of the quasi-localized modes with the sound waves and with each other increases, they de-localize. However, even at the so-called boson peak frequency, where the sound waves become over-damped due to the interaction, the vibrations can be decomposed into local and extended modes. Closely correlated with t.he local vibrations are the local relaxations, which can be envisaged as collective jumps of groups of atoms. With rising temperature both the total jump length and the number of atoms participating increases. In the melt when single jumps are no longer resolved one still observes a collective motion of chains of atoms.","PeriodicalId":20614,"journal":{"name":"Progress of Theoretical Physics Supplement","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64743512","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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