Einstein’s gravity is modified to explain an accelerating universe’s present and past scenarios by numerically exploring different cosmological parameters. A new f(R) gravity model constrained with coupling constants is introduced in the Einstein-Hilbert action to explain current issues and open up new possibilities in gravity physics by fitting the model with newly collected data from observations. It is proposed that the current universe is undergoing an accelerating expansion which behaves as Chaplygin Gas-type dark energy. The values of the coupling constants involved in f(R) gravity are chosen so that the current value of the effective equation of state (ωeff0) is shown within the observational approximation, that is, between −0.8 and −1.0. Cosmological parameters such as deceleration, cosmic jerk, and snap are consistent with the fundamental observational constraint, and their relevance in terms of coupling constant is also emphasized. The viability of the model as well as the existence and origin of scalaron mass are also investigated.
{"title":"Evolutionary phases of the accelerating universe in modified gravity and its solar system test","authors":"Tame Achi, H. S. Singh","doi":"10.1139/cjp-2023-0090","DOIUrl":"https://doi.org/10.1139/cjp-2023-0090","url":null,"abstract":"Einstein’s gravity is modified to explain an accelerating universe’s present and past scenarios by numerically exploring different cosmological parameters. A new f(R) gravity model constrained with coupling constants is introduced in the Einstein-Hilbert action to explain current issues and open up new possibilities in gravity physics by fitting the model with newly collected data from observations. It is proposed that the current universe is undergoing an accelerating expansion which behaves as Chaplygin Gas-type dark energy. The values of the coupling constants involved in f(R) gravity are chosen so that the current value of the effective equation of state (ωeff0) is shown within the observational approximation, that is, between −0.8 and −1.0. Cosmological parameters such as deceleration, cosmic jerk, and snap are consistent with the fundamental observational constraint, and their relevance in terms of coupling constant is also emphasized. The viability of the model as well as the existence and origin of scalaron mass are also investigated.","PeriodicalId":9413,"journal":{"name":"Canadian Journal of Physics","volume":"69 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88320504","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}
We extract the square root of the Minkowski metric using Dirac/Clifford ma- trices. The resulting 4 × 4 operator dS that represents the square root, can be used to transform four vectors between relatively moving observers. This effects the usual Lorentz transformation. In addition it acts on a Dirac bi-spinor. The operator can be used as a Hamiltonian operator to write an equation of motion for a relativistic spinor. This turns out to be the Dirac equation for electrons in standard form, which appears as a transformation of a moving spinor to the rest frame of the spinor. This approach was introduced in paper I of this series for non relativistic spinor particles. We believe that is is a new approach to familiar results.
{"title":"Quantum Equations of Motion and the Geometrical Imperative II: Relativistic","authors":"R. Henriksen","doi":"10.1139/cjp-2022-0311","DOIUrl":"https://doi.org/10.1139/cjp-2022-0311","url":null,"abstract":"We extract the square root of the Minkowski metric using Dirac/Clifford ma- trices. The resulting 4 × 4 operator dS that represents the square root, can be used to transform four vectors between relatively moving observers. This effects the usual Lorentz transformation. In addition it acts on a Dirac bi-spinor. The operator can be used as a Hamiltonian operator to write an equation of motion for a relativistic spinor. This turns out to be the Dirac equation for electrons in standard form, which appears as a transformation of a moving spinor to the rest frame of the spinor. This approach was introduced in paper I of this series for non relativistic spinor particles. We believe that is is a new approach to familiar results.","PeriodicalId":9413,"journal":{"name":"Canadian Journal of Physics","volume":"95 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90441315","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}
In this paper, a quantitative investigation of the non-classical and quantum non-Gaussian characters of the photon-subtracted displaced Fock state ket{psi}=a^kD(alpha)ket{n}, where k is the number of photons subtracted, n is Fock parameter, is performed by using a collection of measures like Wigner logarithmic negativity, linear entropy potential, skew information based measure, and relative entropy of quantum non-Gaussianity. It is noticed that the number of photons subtracted (k) changes the nonclassicality and quantum non-Gaussianity in a significant amount in the regime of small values of the displacement parameter whereas the Fock parameter (n) presents a notable change in the large regime of the displacement parameter. In this respect, the role of the Fock parameter is found to be stronger as compared to the photon subtraction number. Finally, the Wigner function dynamics considering the effects of photon loss channel is used to show that the Wigner negativity can only be detected by highly efficient detectors.
{"title":"Nonclassicality versus quantum non-Gaussianity of photon subtracted displaced Fock state","authors":"Deepak, A. Chatterjee","doi":"10.1139/cjp-2023-0085","DOIUrl":"https://doi.org/10.1139/cjp-2023-0085","url":null,"abstract":"In this paper, a quantitative investigation of the non-classical and quantum non-Gaussian characters of the photon-subtracted displaced Fock state ket{psi}=a^kD(alpha)ket{n}, where k is the number of photons subtracted, n is Fock parameter, is performed by using a collection of measures like Wigner logarithmic negativity, linear entropy potential, skew information based measure, and relative entropy of quantum non-Gaussianity. It is noticed that the number of photons subtracted (k) changes the nonclassicality and quantum non-Gaussianity in a significant amount in the regime of small values of the displacement parameter whereas the Fock parameter (n) presents a notable change in the large regime of the displacement parameter. In this respect, the role of the Fock parameter is found to be stronger as compared to the photon subtraction number. Finally, the Wigner function dynamics considering the effects of photon loss channel is used to show that the Wigner negativity can only be detected by highly efficient detectors.","PeriodicalId":9413,"journal":{"name":"Canadian Journal of Physics","volume":"54 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82107285","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}
We discuss the perceptions and experiences of high school students using Reflective Writing and labatorials to attempt to understand Newtonian concepts of force and motion. The sequencing and content of these activities are centered on targeting students’ key difficulties related to forces and motion. Participants are 210 secondary 5 (grade 11) students, from three private schools in Montreal, who took a physics course during 2017-2018 or 2018-2019. Their ideas and opinions about forces and learning physics were investigated, prior to and following the study, with: (a) three questions from the Force Concept Inventory (FCI); (b) a concept map focused on the relations between force and motion. (c) Pre- and post- semi-structured interviews conducted with 12 participants. The gathered data and interviews indicate that the process of combining Labatorials with Reflective Writing improves students’ attitudes towards learning the subject.
{"title":"High School Students perceptions and experiences of using combined RW and Laboratorials to understand Newton’s Laws of Motion","authors":"Joseph El-Helou, C. Kalman","doi":"10.1139/cjp-2022-0255","DOIUrl":"https://doi.org/10.1139/cjp-2022-0255","url":null,"abstract":"We discuss the perceptions and experiences of high school students using Reflective Writing and labatorials to attempt to understand Newtonian concepts of force and motion. The sequencing and content of these activities are centered on targeting students’ key difficulties related to forces and motion. Participants are 210 secondary 5 (grade 11) students, from three private schools in Montreal, who took a physics course during 2017-2018 or 2018-2019. Their ideas and opinions about forces and learning physics were investigated, prior to and following the study, with: (a) three questions from the Force Concept Inventory (FCI); (b) a concept map focused on the relations between force and motion. (c) Pre- and post- semi-structured interviews conducted with 12 participants. The gathered data and interviews indicate that the process of combining Labatorials with Reflective Writing improves students’ attitudes towards learning the subject.","PeriodicalId":9413,"journal":{"name":"Canadian Journal of Physics","volume":"39 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72559272","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}
In view of nuclear structure calculations, the second Pöschl–Teller potential is parameterized to study nucleon–nucleon and nucleon–nucleus elastic scattering. By exploiting the variable phase approach to potential scattering, phase parameters, cross sections, analyzing powers, etc., are computed and compared with earlier works. The calculated cross sections agree with the experiments below 25 MeV within the error bars for the (n-p) and (n-d) systems.
{"title":"Phase shift and cross section analysis of nucleon–nucleon and nucleon–nucleus scattering using second Pöschl–Teller potential","authors":"P. Sahoo, U. Laha","doi":"10.1139/cjp-2022-0317","DOIUrl":"https://doi.org/10.1139/cjp-2022-0317","url":null,"abstract":"In view of nuclear structure calculations, the second Pöschl–Teller potential is parameterized to study nucleon–nucleon and nucleon–nucleus elastic scattering. By exploiting the variable phase approach to potential scattering, phase parameters, cross sections, analyzing powers, etc., are computed and compared with earlier works. The calculated cross sections agree with the experiments below 25 MeV within the error bars for the (n-p) and (n-d) systems.","PeriodicalId":9413,"journal":{"name":"Canadian Journal of Physics","volume":"321 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80232781","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}
The traversable wormholes are fascinating as the shortcuts in spacetime. This work discusses the geometry of a traversable wormhole with a string cloud as a source in rainbow gravity. The field equations are developed and solved to obtain the wormhole's shape function, cloud's mass density, and string tension. We have calculated the shape function and make it specific to study the dynamics for toy model. Based on the three well-known pairs of rainbow functions (mentioned by Ali and Khalil, 2015), the string cloud's dynamical variables including mass density and string tension are graphically presented. The corresponding energy conditions are also visually depicted. It is found that the source matter (string cloud) of the traversable wormhole must be exotic. However, the positive values of the string tension led to the presence of Casimir and dark energy effects. It is found that the toy model respects the null energy condition for a single pair of rainbow functions, i.e., Rainbow Function Type II. We have concluded that in rainbow gravity theory, the traversable wormhole solutions originating from a string cloud requires the presence of exotic matter to achieve a stable structure.
可穿越的虫洞就像时空中的捷径一样迷人。本作品讨论了彩虹引力中以弦云为源的可穿越虫洞的几何形状。建立并求解了场方程，得到了虫洞的形状函数、云的质量密度和弦张力。对玩具模型的形状函数进行了计算，并使其具体化。基于三对著名的彩虹函数(Ali and Khalil, 2015)，我们用图形表示了弦云的动态变量，包括质量密度和弦张力。相应的能量条件也被直观地描绘出来。发现可穿越虫洞的源物质(弦云)一定是外来的。然而，弦张力的正值导致卡西米尔效应和暗能量效应的存在。发现玩具模型对单双彩虹函数，即彩虹函数II型，遵守零能条件。我们已经得出结论，在彩虹引力理论中，起源于弦云的可穿越虫洞解需要外来物质的存在才能获得稳定的结构。
{"title":"Traversable Wormhole Models Supported by a String Cloud in Rainbow Gravity","authors":"Umber Sheikh, S. Arshad, R. Pinčák","doi":"10.1139/cjp-2023-0054","DOIUrl":"https://doi.org/10.1139/cjp-2023-0054","url":null,"abstract":"The traversable wormholes are fascinating as the shortcuts in spacetime. This work discusses the geometry of a traversable wormhole with a string cloud as a source in rainbow gravity. The field equations are developed and solved to obtain the wormhole's shape function, cloud's mass density, and string tension. We have calculated the shape function and make it specific to study the dynamics for toy model. Based on the three well-known pairs of rainbow functions (mentioned by Ali and Khalil, 2015), the string cloud's dynamical variables including mass density and string tension are graphically presented. The corresponding energy conditions are also visually depicted. It is found that the source matter (string cloud) of the traversable wormhole must be exotic. However, the positive values of the string tension led to the presence of Casimir and dark energy effects. It is found that the toy model respects the null energy condition for a single pair of rainbow functions, i.e., Rainbow Function Type II. We have concluded that in rainbow gravity theory, the traversable wormhole solutions originating from a string cloud requires the presence of exotic matter to achieve a stable structure.","PeriodicalId":9413,"journal":{"name":"Canadian Journal of Physics","volume":"103 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80640149","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}
Online learning environments have been used intensively during the Covid 19 pandemic and are frequently preferred alternative learning environments afterward. On the other hand, the lack of adequate learning applications for online environments negatively affects teaching. The main purpose of this research is to develop Problem-Based Learning (PBL) activities for online learning environments within the scope of Physics course and to reveal the application processes. The study was carried out with 97 students in the fall semester of the 2020-2021 academic year. PBL applications were carried out in online learning environments with the interaction of online groups of 5-7 people through the Zoom program. A qualitative research approach and critical action research model were used in this research. The data were obtained with the help of rubric form, interview, peer assessment, peer group assessment and documents and evaluated with content analysis and descriptive analysis. In the process of PBL activities in online learning environments, students took an active role as a part of their learning processes, interacted constantly with their peers, and demonstrated high-level success in their learning competencies by fulfilling their responsibilities. In online learning environments, there is a need for application examples where all students can demonstrate their process skills and student-centered assessment-evaluation applications that will determine the application outputs.
{"title":"PROBLEM-BASED LEARNING APPLICATIONS IN ONLINE ENVIRONMENTS","authors":"A. Kumaş","doi":"10.1139/cjp-2022-0239","DOIUrl":"https://doi.org/10.1139/cjp-2022-0239","url":null,"abstract":"Online learning environments have been used intensively during the Covid 19 pandemic and are frequently preferred alternative learning environments afterward. On the other hand, the lack of adequate learning applications for online environments negatively affects teaching. The main purpose of this research is to develop Problem-Based Learning (PBL) activities for online learning environments within the scope of Physics course and to reveal the application processes. The study was carried out with 97 students in the fall semester of the 2020-2021 academic year. PBL applications were carried out in online learning environments with the interaction of online groups of 5-7 people through the Zoom program. A qualitative research approach and critical action research model were used in this research. The data were obtained with the help of rubric form, interview, peer assessment, peer group assessment and documents and evaluated with content analysis and descriptive analysis. In the process of PBL activities in online learning environments, students took an active role as a part of their learning processes, interacted constantly with their peers, and demonstrated high-level success in their learning competencies by fulfilling their responsibilities. In online learning environments, there is a need for application examples where all students can demonstrate their process skills and student-centered assessment-evaluation applications that will determine the application outputs.","PeriodicalId":9413,"journal":{"name":"Canadian Journal of Physics","volume":"41 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85201907","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}
High-level electronic structure calculations were conducted for LiC molecule and compared to other theoretical results. The potential energy curves (PECs) for the 18 states originating from the first three dissociation channels of LiC molecule were calculated by the internally contracted multireference configuration interaction (icMRCI) method. The spectral constants, vibrational energy levels are reported. The transition properties for the a2Π, b2Δ, c2Σ-, d2Σ+, and 22Π states are discussed. In addition, the spin-orbit coupling (SOC) effects were taken into account in the electronic transition d2Σ+ - a2Π. The b2Δ and c2Σ- states had radiative lifetimes of approximately 0.03-16.83 and 0.86-8.06 ms, respectively. The d2Σ+ and 22Π states had radiative lifetimes of approximately 1.94 - 64.83 and 0.31 - 16.59 µs, respectively. Between these transitions, the emissions from the d2Σ+ - a2Π, 22Π - c2Σ-, 22Π - b2Δ, and 22Π - a2Π systems were strongest, while the emissions from the c2Σ- - a2Π, b2Δ - a2Π, and 22Π - d2Σ+ systems were weaker. The d2Σ+1/2 state had radiative lifetimes of approximately 3.75 - 29.81 µs. Among the spontaneous emissions of the transitions generated by the d2Σ+1/2 state, the emissions from the d2Σ+1/2 - a2Π1/2 and d2Σ+1/2 - a2Π3/2 systems were relatively strong and easily observed experimentally. The radiative lifetime variation law with the rotational quantum number for the d2Σ+1/2 state at rotational quantum number J ≤ 70 and vibrational quantum number ν ≤ 15 is also presented in this paper. In addition, almost all the strong emissions of the transitions were distributed in the infrared region. It is expected that the results of this study will serve as a helpful reference for future experimental and theoretical studies.
{"title":"Ab initio study on the spectroscopic and radiative properties of lithium monocarbide","authors":"Mingxin Zhou, Shan Sun, Yufeng Gao, Zun-lue Zhu","doi":"10.1139/cjp-2022-0337","DOIUrl":"https://doi.org/10.1139/cjp-2022-0337","url":null,"abstract":"High-level electronic structure calculations were conducted for LiC molecule and compared to other theoretical results. The potential energy curves (PECs) for the 18 states originating from the first three dissociation channels of LiC molecule were calculated by the internally contracted multireference configuration interaction (icMRCI) method. The spectral constants, vibrational energy levels are reported. The transition properties for the a<sup>2</sup>Π, b<sup>2</sup>Δ, c<sup>2</sup>Σ<sup>-</sup>, d<sup>2</sup>Σ<sup>+</sup>, and 2<sup>2</sup>Π states are discussed. In addition, the spin-orbit coupling (SOC) effects were taken into account in the electronic transition d<sup>2</sup>Σ<sup>+</sup> - a<sup>2</sup>Π. The b<sup>2</sup>Δ and c<sup>2</sup>Σ<sup>-</sup> states had radiative lifetimes of approximately 0.03-16.83 and 0.86-8.06 ms, respectively. The d<sup>2</sup>Σ<sup>+</sup> and 2<sup>2</sup>Π states had radiative lifetimes of approximately 1.94 - 64.83 and 0.31 - 16.59 µs, respectively. Between these transitions, the emissions from the d<sup>2</sup>Σ<sup>+</sup> - a<sup>2</sup>Π, 2<sup>2</sup>Π - c<sup>2</sup>Σ<sup>-</sup>, 2<sup>2</sup>Π - b<sup>2</sup>Δ, and 2<sup>2</sup>Π - a<sup>2</sup>Π systems were strongest, while the emissions from the c<sup>2</sup>Σ<sup>-</sup> - a<sup>2</sup>Π, b<sup>2</sup>Δ - a<sup>2</sup>Π, and 2<sup>2</sup>Π - d<sup>2</sup>Σ<sup>+</sup> systems were weaker. The d<sup>2</sup>Σ<sup>+</sup><sub>1/2</sub> state had radiative lifetimes of approximately 3.75 - 29.81 µs. Among the spontaneous emissions of the transitions generated by the d<sup>2</sup>Σ<sup>+</sup><sub>1/2</sub> state, the emissions from the d<sup>2</sup>Σ<sup>+</sup><sub>1/2</sub> - a<sup>2</sup>Π<sub>1/2</sub> and d<sup>2</sup>Σ<sup>+</sup><sub>1/2</sub> - a<sup>2</sup>Π<sub>3/2</sub> systems were relatively strong and easily observed experimentally. The radiative lifetime variation law with the rotational quantum number for the d<sup>2</sup>Σ<sup>+</sup><sub>1/2</sub> state at rotational quantum number J ≤ 70 and vibrational quantum number ν ≤ 15 is also presented in this paper. In addition, almost all the strong emissions of the transitions were distributed in the infrared region. It is expected that the results of this study will serve as a helpful reference for future experimental and theoretical studies.","PeriodicalId":9413,"journal":{"name":"Canadian Journal of Physics","volume":"40 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80807833","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}
Hiba Elarabi, F. Khelfaoui, K. Boudia, F. Labani, M. Hamlat, Ouafaa Sadouki, F. Belkharroubi, F. Faid, A. Bouhemadou, B. Deghfel
The structural, elastic, electronic, and magnetic properties of the CrCoSi, MnCoSi parent half-Heusler (HH) alloys, and their CrMnCo2Si2 derivative double half-Heusler (DHH) compound are studied, utilizing the augmented plane wave method, which is based on density functional theory and implemented in the WIEN2k code. The stability of HH structure of the CrCoSi and MnCoSi alloys has been checked for their non-magnetic and ferromagnetic phases, leading to that the latter phase of the type I arrangement is the most stable. The CrMnCo2Si2 DHH alloy, derivative from the found structural and magnetic ground states of CrCoSi and MnCoSi HH alloys, is constructed and investigated. This DDH as well as its CrCoSi parent HH are found to be resistant to deformation and can be classified as ductile materials, whereas the MnCoSi compound is brittle. By the gradient generalized approximation (GGA), the electronic structures of CrCoSi, MnCoSi, and CrMnCo2Si2compounds exhibit a metallic behavior in the spin-up channel and a semiconducting behavior in the spin-dn channel, with band gaps (half-metallic gaps) of 0.851(0.020), 0.852(0.021), and 0.531(0.002) eV, respectively. The half-metallicity of CrMnCo2Si2 DHH is retained with smaller (larger) band gap (half-metallic gap) of 0.38(0.106) eV than that of GGA, using GGA + U approximation. In addition, the total magnetic moments are found to be 1, 2, and 3 µB for CrCoSi, MnCoSi, and CrMnCo2Si2, respectively. Therefore, these alloys can be good candidates for spinitronic applications due to their half-metallicity.
{"title":"Half-metallicity from CrCoSi and MnCoSi half-Heusler alloys to their derivative double half-Heusler CrMnCo2Si2","authors":"Hiba Elarabi, F. Khelfaoui, K. Boudia, F. Labani, M. Hamlat, Ouafaa Sadouki, F. Belkharroubi, F. Faid, A. Bouhemadou, B. Deghfel","doi":"10.1139/cjp-2022-0251","DOIUrl":"https://doi.org/10.1139/cjp-2022-0251","url":null,"abstract":"The structural, elastic, electronic, and magnetic properties of the CrCoSi, MnCoSi parent half-Heusler (HH) alloys, and their CrMnCo2Si2 derivative double half-Heusler (DHH) compound are studied, utilizing the augmented plane wave method, which is based on density functional theory and implemented in the WIEN2k code. The stability of HH structure of the CrCoSi and MnCoSi alloys has been checked for their non-magnetic and ferromagnetic phases, leading to that the latter phase of the type I arrangement is the most stable. The CrMnCo2Si2 DHH alloy, derivative from the found structural and magnetic ground states of CrCoSi and MnCoSi HH alloys, is constructed and investigated. This DDH as well as its CrCoSi parent HH are found to be resistant to deformation and can be classified as ductile materials, whereas the MnCoSi compound is brittle. By the gradient generalized approximation (GGA), the electronic structures of CrCoSi, MnCoSi, and CrMnCo2Si2compounds exhibit a metallic behavior in the spin-up channel and a semiconducting behavior in the spin-dn channel, with band gaps (half-metallic gaps) of 0.851(0.020), 0.852(0.021), and 0.531(0.002) eV, respectively. The half-metallicity of CrMnCo2Si2 DHH is retained with smaller (larger) band gap (half-metallic gap) of 0.38(0.106) eV than that of GGA, using GGA + U approximation. In addition, the total magnetic moments are found to be 1, 2, and 3 µB for CrCoSi, MnCoSi, and CrMnCo2Si2, respectively. Therefore, these alloys can be good candidates for spinitronic applications due to their half-metallicity.","PeriodicalId":9413,"journal":{"name":"Canadian Journal of Physics","volume":"28 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83443426","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}
Unitarity and the optical theorem are used to derive the reduced density matrices of Compton scattering in the presence of a witness particle. Two photons are initially entangled wherein one photon participates in Compton scattering while the other is a witness, i.e. does not interact with the electron. Unitarity is shown to require that the entanglement entropy of the witness photon does not change after its entangled partner undergoes scattering. The final mutual information of the electron and witness particle's polarizations is shown to be nonzero for low energy Compton scattering. This indicates that the two particles became correlated in spite of no direct interaction. Assuming an initial maximally entangled state, the change in entanglement entropy of the scattered photon's polarization is calculated in terms of Stokes parameters. A common ratio of areas occurs in the final reduced density matrix elements, von Neumann entropies, Stokes parameter, and mutual information. This common ratio consists of the Thomson scattering cross-section and an accessible regularized scattering area.
{"title":"Entanglement Entropy of Compton Scattering with a Witness","authors":"Shanmuka Shivashankara","doi":"10.1139/cjp-2023-0142","DOIUrl":"https://doi.org/10.1139/cjp-2023-0142","url":null,"abstract":"Unitarity and the optical theorem are used to derive the reduced density matrices of Compton scattering in the presence of a witness particle. Two photons are initially entangled wherein one photon participates in Compton scattering while the other is a witness, i.e. does not interact with the electron. Unitarity is shown to require that the entanglement entropy of the witness photon does not change after its entangled partner undergoes scattering. The final mutual information of the electron and witness particle's polarizations is shown to be nonzero for low energy Compton scattering. This indicates that the two particles became correlated in spite of no direct interaction. Assuming an initial maximally entangled state, the change in entanglement entropy of the scattered photon's polarization is calculated in terms of Stokes parameters. A common ratio of areas occurs in the final reduced density matrix elements, von Neumann entropies, Stokes parameter, and mutual information. This common ratio consists of the Thomson scattering cross-section and an accessible regularized scattering area.","PeriodicalId":9413,"journal":{"name":"Canadian Journal of Physics","volume":"46 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84582055","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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