Pub Date : 2024-03-19DOI: 10.1088/1361-6404/ad358c
Xiaoqi Zeng, Ji Chen, Xiaofeng Wang, Mingzhen Shao
We propose a teaching apparatus to simultaneously measure the refractive index and thickness of a thin film. The apparatus includes: a diode laser, a polarizer, a spectrometer, a photodiode and a portable digital multimeter. With the apparatus, we measure the refractive index and thickness of two thin films (a silicon dioxide film on silicon, a silicon nitride film on silicon). The maximum discrepancy between our apparatus and an ellipsometer is 1.4%. We also analyze the errors of our apparatus by numerical simulations. The lab with the apparatus described here has several valuable pedagogical outcomes: 1) understanding the multi-beam interference in a film; 2) applying chi-square minimization; 3) carrying out the nonlinear curve fitting with multiple parameters. The lab can be used in an optical polarization teaching for undergraduate sophomores.
{"title":"Measuring the Refractive Index and Thickness of a Thin Film: an Optical Polarization Experiment","authors":"Xiaoqi Zeng, Ji Chen, Xiaofeng Wang, Mingzhen Shao","doi":"10.1088/1361-6404/ad358c","DOIUrl":"https://doi.org/10.1088/1361-6404/ad358c","url":null,"abstract":"\u0000 We propose a teaching apparatus to simultaneously measure the refractive index and thickness of a thin film. The apparatus includes: a diode laser, a polarizer, a spectrometer, a photodiode and a portable digital multimeter. With the apparatus, we measure the refractive index and thickness of two thin films (a silicon dioxide film on silicon, a silicon nitride film on silicon). The maximum discrepancy between our apparatus and an ellipsometer is 1.4%. We also analyze the errors of our apparatus by numerical simulations. The lab with the apparatus described here has several valuable pedagogical outcomes: 1) understanding the multi-beam interference in a film; 2) applying chi-square minimization; 3) carrying out the nonlinear curve fitting with multiple parameters. The lab can be used in an optical polarization teaching for undergraduate sophomores.","PeriodicalId":505733,"journal":{"name":"European Journal of Physics","volume":"54 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140231098","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 : 2024-03-13DOI: 10.1088/1361-6404/ad336a
Matt Majic, Sophia Geris
Configurations of dipoles, moving point charges and current loops are presented for the dynamic spherical multipoles of the electric and magnetic type, whose fields are the vector spherical wave functions (VSWFs). The configurations produce the VSWFs of a specific degree and order in the limit that they become infinitely small. We find frequency independent configurations for up to degree $n=5$ or higher in some cases, which exceeds the current range of configurations in the literature for up to $n=3$, and our configurations for $n=3$ are simpler. We also investigate the link with anapoles and toroidal multipoles.
{"title":"Configurations of dipoles, moving charges and currents for dynamic spherical multipoles","authors":"Matt Majic, Sophia Geris","doi":"10.1088/1361-6404/ad336a","DOIUrl":"https://doi.org/10.1088/1361-6404/ad336a","url":null,"abstract":"\u0000 Configurations of dipoles, moving point charges and current loops are presented for the dynamic spherical multipoles of the electric and magnetic type, whose fields are the vector spherical wave functions (VSWFs). The configurations produce the VSWFs of a specific degree and order in the limit that they become infinitely small. We find frequency independent configurations for up to degree $n=5$ or higher in some cases, which exceeds the current range of configurations in the literature for up to $n=3$, and our configurations for $n=3$ are simpler. We also investigate the link with anapoles and toroidal multipoles.","PeriodicalId":505733,"journal":{"name":"European Journal of Physics","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140247810","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 : 2024-03-13DOI: 10.1088/1361-6404/ad336b
Boxi Li, Chunling Liu
Using the concept of heterostructures in Semiconductor Physics and the similarity between Schrödinger Equation and the vibration equation of the one-dimension string-ball chain system, we create a heterojunction in our string-ball chain system by assembling a string-ball chain with two kinds of mass in lattice-matched and the unmatched system and study the two systems in first principle calculation, theoretical analysis, and experiment perspectives. A discontinuity in frequency dependence is observed in the matched system, while a phase transition is discovered in the unmatched system. A proper theoretical analysis based on the wave function is also given to explain those phenomena.
{"title":"Resonance frequency band structure in heterojunction of one-dimension string-ball chain system","authors":"Boxi Li, Chunling Liu","doi":"10.1088/1361-6404/ad336b","DOIUrl":"https://doi.org/10.1088/1361-6404/ad336b","url":null,"abstract":"\u0000 Using the concept of heterostructures in Semiconductor Physics and the similarity between Schrödinger Equation and the vibration equation of the one-dimension string-ball chain system, we create a heterojunction in our string-ball chain system by assembling a string-ball chain with two kinds of mass in lattice-matched and the unmatched system and study the two systems in first principle calculation, theoretical analysis, and experiment perspectives. A discontinuity in frequency dependence is observed in the matched system, while a phase transition is discovered in the unmatched system. A proper theoretical analysis based on the wave function is also given to explain those phenomena.","PeriodicalId":505733,"journal":{"name":"European Journal of Physics","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140245371","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 : 2024-03-13DOI: 10.1088/1361-6404/ad336c
Apekshya Ghimire, Chandralekha Singh
In this research, we investigated the impact of peer collaboration and changes from individual to group performance of graduate students on the Conceptual Survey of Electricity and Magnetism (CSEM) without any guidance from the course instructor. We define construction of knowledge as a case in which the group answered the question correctly but in the individual administration of the survey before the group work, one member gave the correct answer and the other gave the incorrect answer. We find that there was a significant improvement in the performance of students after peer interaction in pairs, which was mostly attributed to construction of knowledge. However, students had very few opportunities to co-construct knowledge as there were hardly any situations in which neither student in a group provided a correct answer. We analyzed the effect size for improvement from individual to group scores for each CSEM item to understand the characteristics of these questions that led to productive group interaction. We also compared the group performance of the graduate students to the introductory physics students in a prior study using the CSEM to get insight into the concepts that showed differences for the two groups and those that were challenging for both groups of students. Our findings can motivate physics instructors to incorporate group interactions both inside and outside of the classroom even without the instructor involvement so that students at all levels can learn from each other and develop a functional understanding of the underlying concepts.
{"title":"How often does unguided peer interaction lead to correct response consensus? An example from Conceptual Survey of Electricity and Magnetism","authors":"Apekshya Ghimire, Chandralekha Singh","doi":"10.1088/1361-6404/ad336c","DOIUrl":"https://doi.org/10.1088/1361-6404/ad336c","url":null,"abstract":"\u0000 In this research, we investigated the impact of peer collaboration and changes from individual to group performance of graduate students on the Conceptual Survey of Electricity and Magnetism (CSEM) without any guidance from the course instructor. We define construction of knowledge as a case in which the group answered the question correctly but in the individual administration of the survey before the group work, one member gave the correct answer and the other gave the incorrect answer. We find that there was a significant improvement in the performance of students after peer interaction in pairs, which was mostly attributed to construction of knowledge. However, students had very few opportunities to co-construct knowledge as there were hardly any situations in which neither student in a group provided a correct answer. We analyzed the effect size for improvement from individual to group scores for each CSEM item to understand the characteristics of these questions that led to productive group interaction. We also compared the group performance of the graduate students to the introductory physics students in a prior study using the CSEM to get insight into the concepts that showed differences for the two groups and those that were challenging for both groups of students. Our findings can motivate physics instructors to incorporate group interactions both inside and outside of the classroom even without the instructor involvement so that students at all levels can learn from each other and develop a functional understanding of the underlying concepts.","PeriodicalId":505733,"journal":{"name":"European Journal of Physics","volume":"419 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140246956","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 : 2024-03-12DOI: 10.1088/1361-6404/ad32dc
Jed Brody, Kristen Gram
We present, for the non-specialist, an experimental implementation of Shor’s factoring algorithm. We are unaware of any other single reference that explains, in a beginner-friendly way, complete circuits that implement Shor’s algorithm. We perform the experiment with IBM quantum processors, which are remotely accessible online for free. We reproducibly factor 15 with one 7-qubit processor (ibm_perth), while four other quantum processors exhibit excessive error.
我们为非专业人士介绍了 Shor 因式分解算法的实验实现。我们没有发现任何其他参考文献以初学者易于理解的方式解释了实现肖尔算法的完整电路。我们使用 IBM 量子处理器进行实验，这些处理器可以在网上免费远程访问。我们使用一个 7 量子比特处理器（ibm_perth）可重复计算出 15 个因子，而其他四个量子处理器则表现出过大的误差。
{"title":"Factoring 15 with a remote quantum computer: A complete guide for beginners","authors":"Jed Brody, Kristen Gram","doi":"10.1088/1361-6404/ad32dc","DOIUrl":"https://doi.org/10.1088/1361-6404/ad32dc","url":null,"abstract":"\u0000 We present, for the non-specialist, an experimental implementation of Shor’s factoring algorithm. We are unaware of any other single reference that explains, in a beginner-friendly way, complete circuits that implement Shor’s algorithm. We perform the experiment with IBM quantum processors, which are remotely accessible online for free. We reproducibly factor 15 with one 7-qubit processor (ibm_perth), while four other quantum processors exhibit excessive error.","PeriodicalId":505733,"journal":{"name":"European Journal of Physics","volume":"233 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140249410","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 : 2024-03-11DOI: 10.1088/1361-6404/ad3269
C. Villegas, David Romero-Abad, W. Rojas
The propagation of light through a thin film interfaced between two semi-infinite media serves as a compelling illustration for elucidating electromagnetic wave interactions with matter at the undergraduate level. Despite its pedagogical significance and diverse technological applications, this model often receives inadequate attention in foundational electromagnetism literature, limiting early student exposure to this emblematic concept. In this pedagogical initiative, we present a comprehensive analysis of electromagnetic wave propagation through a dielectric medium positioned between semi-infinite media. We examine interference phenomena arising from back-and-forth reflected waves within the dielectric, focusing on the coherent and incoherent reflection regimes as limiting cases. Employing rigorous analytical treatment, we delineate transmittance and reflectance profiles, offering students a lucid understanding of how the refractive index's real and imaginary components compete and manifest under specific conditions. This analytical approach enhances students' comprehension of electromagnetic wave behavior within diverse mediums. Furthermore, we extend this theoretical foundation to practical applications, emphasizing renewable energy contexts. By calculating absorptance, we estimate the maximum photo-generated current and power conversion efficiency of a prototype solar cell, establishing a tangible link between theoretical knowledge and real-world solar energy utilization.
{"title":"Elucidating the coherent and incoherent reflection of plane-waves in finite thickness media: a practical pedagogical application","authors":"C. Villegas, David Romero-Abad, W. Rojas","doi":"10.1088/1361-6404/ad3269","DOIUrl":"https://doi.org/10.1088/1361-6404/ad3269","url":null,"abstract":"\u0000 The propagation of light through a thin film interfaced between two semi-infinite media serves as a compelling illustration for elucidating electromagnetic wave interactions with matter at the undergraduate level. Despite its pedagogical significance and diverse technological applications, this model often receives inadequate attention in foundational electromagnetism literature, limiting early student exposure to this emblematic concept. In this pedagogical initiative, we present a comprehensive analysis of electromagnetic wave propagation through a dielectric medium positioned between semi-infinite media. We examine interference phenomena arising from back-and-forth reflected waves within the dielectric, focusing on the coherent and incoherent reflection regimes as limiting cases. Employing rigorous analytical treatment, we delineate transmittance and reflectance profiles, offering students a lucid understanding of how the refractive index's real and imaginary components compete and manifest under specific conditions. This analytical approach enhances students' comprehension of electromagnetic wave behavior within diverse mediums. Furthermore, we extend this theoretical foundation to practical applications, emphasizing renewable energy contexts. By calculating absorptance, we estimate the maximum photo-generated current and power conversion efficiency of a prototype solar cell, establishing a tangible link between theoretical knowledge and real-world solar energy utilization.","PeriodicalId":505733,"journal":{"name":"European Journal of Physics","volume":"87 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140252007","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 : 2024-03-07DOI: 10.1088/1361-6404/ad312f
S. Ivković, Jelena Jovanović, B. Obradović
The basic premise of this work was to create a simple experimental setup for the demonstration of Fresnel-Arago laws and the realization of an experimental exercise. An Iceland calcite is used as a beam splitter, and by adding a diverging lens (commonly used to magnify the image), a large image of overlapping spots is obtained at a short distance, visible to a wide audience. Additionally, by placing a diverging lens at different distances from the calcite, the level of the spots overlapping can be changed. The interference image is photographed by a smartphone and processed by one of the available applications for quantitative image processing. The experiment was carried out using red and green laser light. The same setup, with a diverging lens, also allows the reconstruction of the original Fresnel and Arago experiment with a thin metal cylinder. Quick and easy construction, relatively simple processing of the interference image, without the use of expensive devices (CCD camera, beam splitter, beam expander), and the good agreement between the nominal and measured laser light wavelengths, make this setup very suitable for realization as a student exercise for undergraduate and master's students.
{"title":"Fresnel-Arago laws: an easily feasible demonstration and laboratory exercise for students","authors":"S. Ivković, Jelena Jovanović, B. Obradović","doi":"10.1088/1361-6404/ad312f","DOIUrl":"https://doi.org/10.1088/1361-6404/ad312f","url":null,"abstract":"\u0000 The basic premise of this work was to create a simple experimental setup for the demonstration of Fresnel-Arago laws and the realization of an experimental exercise. An Iceland calcite is used as a beam splitter, and by adding a diverging lens (commonly used to magnify the image), a large image of overlapping spots is obtained at a short distance, visible to a wide audience. Additionally, by placing a diverging lens at different distances from the calcite, the level of the spots overlapping can be changed. The interference image is photographed by a smartphone and processed by one of the available applications for quantitative image processing. The experiment was carried out using red and green laser light. The same setup, with a diverging lens, also allows the reconstruction of the original Fresnel and Arago experiment with a thin metal cylinder. Quick and easy construction, relatively simple processing of the interference image, without the use of expensive devices (CCD camera, beam splitter, beam expander), and the good agreement between the nominal and measured laser light wavelengths, make this setup very suitable for realization as a student exercise for undergraduate and master's students.","PeriodicalId":505733,"journal":{"name":"European Journal of Physics","volume":"32 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140260593","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 : 2024-03-07DOI: 10.1088/1361-6404/ad3130
Satadal Bhattacharyya, J. Mitra
We have calculated the partition function and hence the energy and the specific heat of a two-particle system in $n$ numbers of finite nondegenerate energy levels of equal spacing distributed according to classical and quantum statistics. We have then extended our study for $N$ identical particles placed in $1$-D harmonic oscillator potential. It is observed that the specific heat of bosons and fermions are exactly the same in this potential at any temperature, and at high temperature the results are similar to that for the classical particles. The partition function of a system of two particles placed in $2$-D harmonic oscillator potential has also been determined as comparison.
{"title":"Study of Thermodynamic Properties of $N$ Particles in $1$-Dimensional Harmonic Oscillator Potential","authors":"Satadal Bhattacharyya, J. Mitra","doi":"10.1088/1361-6404/ad3130","DOIUrl":"https://doi.org/10.1088/1361-6404/ad3130","url":null,"abstract":"\u0000 We have calculated the partition function and hence the energy and the specific heat of a two-particle system in $n$ numbers of finite nondegenerate energy levels of equal spacing distributed according to classical and quantum statistics. We have then extended our study for $N$ identical particles placed in $1$-D harmonic oscillator potential. It is observed that the specific heat of bosons and fermions are exactly the same in this potential at any temperature, and at high temperature the results are similar to that for the classical particles. The partition function of a system of two particles placed in $2$-D harmonic oscillator potential has also been determined as comparison.","PeriodicalId":505733,"journal":{"name":"European Journal of Physics","volume":"38 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140258435","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 : 2024-03-07DOI: 10.1088/1361-6404/ad3158
P. Romano
A comparison between two different techniques useful to measure the current-voltage (I-V) characteristics of conducting materials or devices will be presented, suitable for an undergraduate laboratory devoted to the electrical measurements. First, I-V curves of linear resistors with known nominal resistance are measured by using the simplest version of a DC method and an AC method, in order to settle the experimental procedure. Then, nonlinear I-V curves of a superconductor are measured with the same procedures at different temperatures down to 77K.
{"title":"How to measure the current-voltage characteristics of Ohmic conductors and superconductors","authors":"P. Romano","doi":"10.1088/1361-6404/ad3158","DOIUrl":"https://doi.org/10.1088/1361-6404/ad3158","url":null,"abstract":"\u0000 A comparison between two different techniques useful to measure the current-voltage (I-V) characteristics of conducting materials or devices will be presented, suitable for an undergraduate laboratory devoted to the electrical measurements. First, I-V curves of linear resistors with known nominal resistance are measured by using the simplest version of a DC method and an AC method, in order to settle the experimental procedure. Then, nonlinear I-V curves of a superconductor are measured with the same procedures at different temperatures down to 77K.","PeriodicalId":505733,"journal":{"name":"European Journal of Physics","volume":"41 20","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140259292","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 : 2024-03-07DOI: 10.1088/1361-6404/ad312d
Alejandro Romanelli
The thermodynamic approach developed in the Ref. 6 achieves, among other things, an adequate description of the experimental pressure-volumes diagrams of Stirling engines. However, an unusual and relevant result of such an approach is that, during part of its cycle, the working gas reaches temperatures above and below the temperatures of the two thermal reservoirs that keep the engine running. Within this framework, the present paper essentially shows that the predictions of the above model are not in conflict with the second law of thermodynamics. Analytical expressions for the entropies of the working gas and the environment are developed, and the definition of efficiency is discussed. The theoretical results are applied numerically to a specific Stirling engine.
{"title":"Entropy and the Stirling engine","authors":"Alejandro Romanelli","doi":"10.1088/1361-6404/ad312d","DOIUrl":"https://doi.org/10.1088/1361-6404/ad312d","url":null,"abstract":"\u0000 The thermodynamic approach developed in the Ref. 6 achieves, among other things, an adequate description of the experimental pressure-volumes diagrams of Stirling engines. However, an unusual and relevant result of such an approach is that, during part of its cycle, the working gas reaches temperatures above and below the temperatures of the two thermal reservoirs that keep the engine running. Within this framework, the present paper essentially shows that the predictions of the above model are not in conflict with the second law of thermodynamics. Analytical expressions for the entropies of the working gas and the environment are developed, and the definition of efficiency is discussed. The theoretical results are applied numerically to a specific Stirling engine.","PeriodicalId":505733,"journal":{"name":"European Journal of Physics","volume":"5 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140259993","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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