New Quantum Exchange collection resources
https://www.compadre.org/quantum/
The latest material additions to the Quantum Exchange.en-USCopyright 2021, ComPADRE.orgeditor@thequantumexchange.orgeditor@thequantumexchange.orgWed, 12 May 2021 10:32:13 ESThttp://blogs.law.harvard.edu/tech/rsshttps://www.compadre.org/portal/services/images/LogoSmallQuantum.gifQuantum Exchange
https://www.compadre.org/quantum/
12535Characterizing representational learning: A combined simulation and tutorial on perturbation theory
https://www.compadre.org/quantum/items/detail.cfm?ID=15688
Analyzing, constructing, and translating between graphical, pictorial, and mathematical representations of physics ideas and reasoning flexibly through them (“representational competence”) is a key characteristic of expertise in physics but is a challenge for learners to develop. Interactive computer simulations and University of Washington style tutorials both have affordances to support representational learning. This article describes work to characterize students’ spontaneous use of representations before and after working with a combined simulation and tutorial on first-order energy corrections in the context of quantum-mechanical time-independent perturbation theory. Data were collected from two institutions using pre-, mid-, and post-tests to assess short- and long-term gains. A representational competence level framework was adapted to devise level descriptors for the assessment items. The results indicate an increase in the number of representations used by students and the consistency between them following the combined simulation tutorial. The distributions of representational competence levels suggest a shift from perceptual to semantic use of representations based on their underlying meaning. In terms of activity design, this study illustrates the need to support students in making sense of the representations shown in a simulation and in learning to choose the most appropriate representation for a given task. In terms of characterizing representational abilities, this study illustrates the usefulness of a framework focusing on perceptual, syntactic, and semantic use of representations.Education Foundations/Problem Solving/Representational Usehttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15688Wed, 12 May 2021 10:32:13 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15688Enhancing student learning of two-level quantum systems with interactive simulations
https://www.compadre.org/quantum/items/detail.cfm?ID=15589
The QuVis Quantum Mechanics Visualization project aims to address challenges of quantum mechanics instruction through the development of interactive simulations for the learning and teaching of quantum mechanics. In this article, we describe the evaluation of simulations focusing on two-level systems developed as part of the Institute of Physics Quantum Physics resources. Simulations are research-based and have been iteratively refined using student feedback in individual observation sessions and in-class trials. We give evidence that these simulations are helping students learn quantum mechanics concepts at both the introductory and advanced undergraduate level, and that students perceive simulations to be beneficial to their learning.Quantum Physics/Spin and Finite Dimensional Systems/Two-Level Systemhttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15589Tue, 11 May 2021 15:16:37 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15589The Difference Between a Probability and a Probability Density
https://www.compadre.org/quantum/items/detail.cfm?ID=15585
Learning introductory quantum physics is challenging, in part due to the different paradigms in classical mechanics and quantum physics. Classical mechanics is deterministic in that the equations of motion and the initial conditions fully determine a particle’s trajectory. Quantum physics is an inherently probabilistic theory in that only probabilities for measurement outcomes can be determined. Prior to studying quantum physics, students will typically have little experience with probabilistic analyses of physical systems, and thus probability may be a conceptual hurdle for introductory quantum physics students. This article describes two interactive simulations developed as part of the QuVis Quantum Mechanics Visualization Project that aim to bridge the gap between classical mechanics and quantum physics using probabilistic analyses of classical systems. The simulations illustrate how a probability density can be obtained for two classical systems well known to students. The key learning goals of the simulations are to introduce students to probability densities and to help students distinguish between a probability and a probability density. The simulations build on previous work by Bao and Redish, who developed an activity that used pseudo-random video frames of a glider in harmonic motion to derive a classical probability density for this system, and a University of Washington quantum mechanics tutorial focusing on probability and probability density for a classical system. Interactive simulations allow students to easily carry out experiments and change variables that would be difficult to do with real equipment, and help students connect multiple representations by showing explicitly how they are linked. The simulations described here only require basic knowledge of algebra and classical mechanics. They run on touchscreen devices as well as desktop computers, and can be run in a standard web browser from the QuVis website or downloaded for offline use.Quantum Physics/Probability, Waves, and Interferencehttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15585Tue, 11 May 2021 15:06:41 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15585Enhancing student visual understanding of the time evolution of quantum systems
https://www.compadre.org/quantum/items/detail.cfm?ID=14999
Time dependence is of fundamental importance for the description of quantum systems, but is particularly difficult for students to master. We describe the development and evaluation of a combined simulation-tutorial to support the development of visual understanding of time dependence in quantum mechanics. The associated interactive simulation shows the time dependence of an energy eigenstate and a superposition state, and how the time dependence of the probability density arises from that of the wave function. In order to assess transitions in student thinking, we developed a framework to characterize student responses in terms of real and complex mathematical reasoning and classical and quantum visual reasoning. The results of pre-, mid-, and post-tests indicate that the simulation-tutorial supports the development of visual understanding of time dependence, and that visual reasoning is correlated with improved student performance on a question relating to the time evolution of the wave function and the probability density. The results also indicate that the analogy of a classical standing wave for the infinite well energy eigenfunctions may be problematic in cueing incorrect ideas of time dependence.Quantum Physics/Foundations and Measurements/Time Dependencehttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=14999Tue, 11 May 2021 15:00:17 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=14999A new multimedia resource for teaching quantum mechanics concepts
https://www.compadre.org/quantum/items/detail.cfm?ID=12965
We describe a collection of interactive animations and visualizations for teaching quantum mechanics. The animations can be used at all levels of the undergraduate curriculum. Each animation includes a step-by-step exploration that explains the key points. The animations and instructor resources are freely available. By using a diagnostic survey, we report substantial learning gains for students who have worked with the animations.Education Practices/Instructional Material Design/Simulationhttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=12965Tue, 04 May 2021 09:21:51 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=12965I suddenly have to move my face-to-face physics/astronomy course online!
https://www.compadre.org/quantum/items/detail.cfm?ID=15441
This essay provides help for instructors needing to teach their courses online. It includes both basic principles and considerations for running a remote class and a list of resources that can used for the transition.
This is part of a collection of Expert Recommendations on PhysPort, written to help instructors with their classes.Education Practices/Technology/Distance Educationhttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15441Mon, 10 Aug 2020 17:42:46 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15441Experimenting from a Distance: Remote Controlled Lab experiments for teaching Physics at High-school
https://www.compadre.org/quantum/items/detail.cfm?ID=15428
This report provides information about the purpose, background, and operation of Remote Controlled Labs (RCL) for physics teaching. These online, user-controlled labs provide students with access to experiments that are generally too expensive, too complicated, and/or too dangerous for most schools or colleges to run. The report begins with descriptions of the overall goals and learning outcomes for remote labs. It then gives details regarding eleven available labs. These include Millikan's oil-drop experiment, Rutherford scattering, the speed of light, the photoelectric effect, I-V characteristics of semiconductor devices, and radioactivity.
Both German and English versions of the report are available.Education Practices/Technology/Distance Educationhttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15428Mon, 29 Jun 2020 12:35:23 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15428RCL - Remotely Controlled Laboratories
https://www.compadre.org/quantum/items/detail.cfm?ID=8506
The purpose of this web site is to provide Remote Controlled Labs (RCLs) to users on the internet. These are real experiments which can be executed by a client using a standard web browser interacting with a web server controlling the experiment. Web cams allow the user to observe the on-going experiment. The experiments are designed to encourage interactive exploration by students and emphasize the importance of experiments in physics.
The labs available include Millikan's oil-drop experiment, Rutherford scattering, the speed of light, the photoelectric effect, I-V characteristics, radioactivity, and control of robots.Modern Physics/Generalhttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=8506Mon, 29 Jun 2020 12:11:19 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=8506Millikan Oil Drop Experiment JS
https://www.compadre.org/quantum/items/detail.cfm?ID=15215
The Millikan Oil Drop Exploration is a virtual version of the Millikan's experiment. The experiment is based on balancing forces: the gravitational pull down on an oil drop and the electric force up on ionized particles. The simulation includes a schematic of the apparatus and simulated microscope viewing the oil drops. The oil drops fall and enter the a region where they can be seen through the microscope. Turning on an applied voltage provides a force that can, if adjusted correctly, exactly balance the gravitational force on the drop.
The Millikan Oil Drop Java applet was written by Slavo Tuleja. It was converted from Java to JavaScript by W. Christian using the <a href="https://chemapps.stolaf.edu/swingjs/site/swingjs/examples/about.html">SwingJS </a> system developed at St. Olaf College.Quantum Physics/Quantum Experimentshttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15215Thu, 25 Jun 2020 18:26:15 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15215Design and validation of a two-tier questionnaire on basic aspects in quantum mechanics
https://www.compadre.org/quantum/items/detail.cfm?ID=15070
We present the design, statistical analysis, and validation of a questionnaire to assess students’ knowledge about basic aspects of quantum mechanics (QM). The QM evaluation (QME) is a true-false and multiple-choice mixed questionnaire that features 10 two-tier items spanning three relevant themes in quantum mechanics: wave behavior of matter, measurement, and atoms and electrons behavior. Its validity was assessed through a pilot administration to students and interviews with course instructors. We checked its internal consistency using both classic test theory and Rasch analysis to account for the different difficulty of each tier and for different scoring methods of the items. The questionnaire was administered to about 450 undergraduate physics students and high school physics teachers. Data show that it is a reliable instrument and all items have a good discriminatory power. Since the test does not require an advanced mathematical knowledge, it ideally lends itself to probe students’ knowledge about quantum mechanics in a variety of university courses, from the introductory ones to those more formal and mathematically oriented.Quantum Physics/Generalhttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15070Mon, 15 Jun 2020 16:26:28 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15070Physlet Quantum Physics - The Need for a Quantum Theory
https://www.compadre.org/quantum/items/detail.cfm?ID=15338
Physlet Quantum Physics Section 3: The Need for a Quantum Theory provides simulation-based interactive resources that illustrate the experiments that motivated the creation of quantum mechanics. Topics include blackbody radiation, that photoelectric effect, Compton scattering, atomic spectra, and electron diffraction. Each chapter contains a set of explorations explaining the experiments and their implications and a set of qualitative and quantitative problems for students.
The 3rd edition of Physlet Quantum Physics has been ported in its entirety to HTML 5 using the SwingJS platform developed by Robert Hansen at St. Olaf College. These exercises can be accessed using an modern browser on any device.Quantum Physics/Quantum Experimentshttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15338Sun, 19 Jan 2020 09:56:57 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15338Physlet Quantum Physics - Special Relativity
https://www.compadre.org/quantum/items/detail.cfm?ID=15269
Physlet Quantum Physics Section 2: Special Relativity provides simulation-based interactive resources that illustrate the basic concepts of special relativity. The chapters in this section cover the relativistic properties of spacetime and relativistic energy, momentum, and Doppler effect. Each chapter includes both tutorial explorations and problems for the student to apply the concepts.
The 3rd edition of Physlet Quantum Physics has been ported in its entirety to HTML 5 using the SwingJS platform developed by Robert Hansen at St. Olaf College. These exercises can be accessed using an modern browser on any device.Relativity/Special Relativityhttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15269Thu, 02 Jan 2020 17:41:43 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15269Physlet Quantum Physics - Introduction
https://www.compadre.org/quantum/items/detail.cfm?ID=15252
Physlet Quantum Physics Section 1: Introduction illustrates the technology used in the Physlet Quantum Physics interactive text. In this text, javascript simulations are used to illustrate and explore concepts in special relativity and quantum physics. The examples provided include running and exploring animated simulations, interacting with simulations to gather data, and input of formulas.
The 3rd edition of Physlet Quantum Physics has been ported in its entirety to HTML 5 using the SwingJS platform developed by Robert Hansen at St. Olaf College. These exercises can be accessed using an modern browser on any device.Quantum Physics/Generalhttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15252Thu, 02 Jan 2020 16:37:13 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15252Computation and Problem Solving in Undergraduate Physics
https://www.compadre.org/quantum/items/detail.cfm?ID=15250
Computation and Problem Solving in Undergraduate Physics (CPSUP) is a collection of texts providing instruction in the use of computer-based symbolic and numerical approaches to problem solving in several areas of physics. The collection includes descriptions of several computational tools: IDL, MATLAB, OCTAVE, PYTHON, MAXIMA, MAPLE, MATHEMATICA, PROGRAMMING, FORTRAN, LSODE, MUDPACK, C, NUMERICAL RECIPES, LaTeX, and TGIF, and chapters illustrating the application of these tools to solving ordinary differential equations, evaluating integrals, finding roots, and (coming) solving partial differential equations via finite difference and finite element methods. Physical examples are drawn from mechanics, electromagnetic theory, quantum mechanics, statistical mechanics, and several other areas of physics. Provided are a full text including all the computational tools listed above as well as versions of the text that focus on two of the tools as well as C and FORTRAN programming. Appendices introduce LaTeX and TGIF, a UNIX-based program for creating elaborate two-dimensional figures. All programs and data files used are available for download.
The curricular development out of which this book has arisen has been guided since the mid 1970's by Professor of Physics David M. Cook and has been carried out in the Department of Physics at Lawrence University. General Physics/Computational Physicshttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15250Thu, 02 Jan 2020 12:07:14 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15250Developing and Evaluating Research-Based Learning Tools for Quantum Mechanics
https://www.compadre.org/quantum/items/detail.cfm?ID=15123
Here I present my work on developing and evaluating research-based learning tools for quantum mechanics. In particular, I will discuss the development and evaluation of two Quantum Interactive Learning Tutorials (QuILTs) focusing on Degenerate Perturbation Theory (DPT) and a System of Identical Particles. The QuILTs are guided by several learning theories from cognitive science and strive to help students develop a more robust understanding of the concepts covered. The investigation was carried out in advanced quantum mechanics courses by administering free-response and multiple-choice questions and conducting individual interviews with students. It was found that students share many common difficulties related to relevant physics concepts. They had difficulty with mathematical sense-making and applying linear algebra and combinatorics concepts correctly in this novel context of quantum mechanics. I describe how the research on student difficulties was used as a guide to develop and evaluate the QuILTs, which strives to help students develop a functional understanding of concepts necessary for DPT and a system of identical particles. I also discuss the development and validation of the DPT QuILT focusing on these issues and its in-class evaluation in the undergraduate and graduate courses that focused on these issues.Quantum Physics/Approximation Techniqueshttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15123Tue, 30 Jul 2019 12:57:04 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15123Oersted Lecture 2014: Physics education research and teaching modern Modern Physics
https://www.compadre.org/quantum/items/detail.cfm?ID=15069
Modern Physics has been used as a label for most of physics that was developed since the discovery of X-rays in 1895. Yet, we are teaching students who would not use the label “modern” for anything that happened before about 1995, when they were born. So, are we and our students in worlds that differ by a century? In addition to content, sometimes our students and we have differing views about methods and styles of teaching. A modern course in any topic of physics should include applications of contemporary research in physics education and the learning sciences as well as research and developments in methods of delivering the content. Thus, when we consider teaching Modern Physics, we are challenged with deciding what the content should be, how to adjust for the ever increasing information on how students learn physics, and the constantly changing tools that are available to us for teaching and learning. When we mix all of these together, we can teach modern Modern Physics or maybe teach Modern Physics modernly.General Physics/Physics Education Research/Reflections and Visionshttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15069Wed, 05 Jun 2019 15:28:18 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15069Teaching Qualitative Energy-eigenfunction Shape with Physlets
https://www.compadre.org/quantum/items/detail.cfm?ID=15063
More than 35 years ago, French and Taylor1 outlined an approach to teach students and teachers alike how to understand “qualitative plots of bound-state wave functions.” They described five fundamental statements based on the quantum-mechanical concepts of probability and energy (total and potential), which could be used to deduce the shape of energy eigenfunctions. Despite these important and easy-to-follow statements, this approach has not been universally adopted in the teaching of quantum mechanics.2 For example, recent studies have shown that students' conceptual understanding of quantum mechanics on all levels is surprisingly lacking3 and that misconceptions are universal,4 including that of the relationship between the potential energy function and the resulting energy eigenfunction shape. At the same time, the teaching of quantum mechanical concepts in introductory physics has become increasingly important given the modern technological applications that are based on quantum theory (e.g., PET scans and MRIs). However, most treatments of quantum theory on the introductory level are cursory at best, leaving students with the impression that quantum mechanics is little more than abstract mathematics (a belief that remains with students in their future courses).Quantum Physics/Probability, Waves, and Interferencehttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=15063Tue, 28 May 2019 17:05:10 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=15063Comparing Students performance in QM between China and US
https://www.compadre.org/quantum/items/detail.cfm?ID=14660
This paper discusses a comparative study on American and Chinese students’ conceptual understanding of quantum mechanics. We administered the Quantum Mechanics Survey (QMS) to over 400 undergraduate students from 10 universities in China and the United States. The results showed that students in American universities performed better than their Chinese peers on the QMS.Education Foundations/Societal Issues/International Issueshttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=14660Thu, 01 Mar 2018 22:25:00 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=14660Student understanding of the measurable effects of relative phases in superposition states
https://www.compadre.org/quantum/items/detail.cfm?ID=14659
Quantum states have complex probability amplitudes that are sometimes represented by positive real numbers multiplied by complex exponentials. Although the overall phase of a superposition state does not affect the probabilities, the relative phases between the component basis states can have measurable effects. A thorough grasp of relative phase is needed for students to understand various key ideas in quantum mechanics, including quantum interference and time dependence. We present preliminary results from an investigation into student understanding of the measurable effects of relative phases that was conducted in sophomore- and junior-level quantum mechanics courses at the University of Washington (UW). The findings suggest that many students do not recognize that relative phases have measureable effects and tend to overlook the important role that complex numbers play in quantum mechanics.Quantum Physics/Foundations and Measurements/Probability and Interferencehttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=14659Thu, 01 Mar 2018 18:47:50 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=14659The use of ACER to develop and analyze student responses to expectation value problems
https://www.compadre.org/quantum/items/detail.cfm?ID=14593
In this study we use the ACER framework to investigate how students perform the expectation value in quantum mechanics. Students were given an exam question that required the use of the generalized uncertainty principle to find the lower bound of ΔAΔB for different angular momentum operators. This question requires students to use several mathematical tools, but in this study we focus on the expectation value. The data are analyzed using the ACER framework and we give special attention to students’ choice of mathematical representation. Of the four components in the ACER framework (activation, construction, execution, and reflection), we find that in our question the activation step presents the largest stumbling block for students. We also discuss the limitations of the ACER framework for this type of investigation.Quantum Physics/Foundations and Measurements/Uncertainty Principleshttps://www.compadre.org/quantum/bulletinboard/Thread.cfm?ID=14593Wed, 28 Feb 2018 15:39:06 ESThttps://www.compadre.org/quantum/items/detail.cfm?ID=14593