New Quantum Exchange collection resources
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The latest material additions to the Quantum Exchange.en-USCopyright 2016, ComPADRE.orgeditor@thequantumexchange.orgeditor@thequantumexchange.orgWed, 23 Dec 2015 19:40:09 ESThttp://blogs.law.harvard.edu/tech/rsshttp://www.compadre.org/portal/services/images/LogoSmallQuantum.gifQuantum Exchange
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12535Student difficulties with quantum states while translating state vectors in Dirac notation to wave functions in position and momentum representations
http://www.thequantumexchange.org/items/detail.cfm?ID=13873
Dirac notation is often used in upper level quantum mechanics courses, but students struggle with this representation. To investigate the difficulties that advanced students (i.e., upper-level undergraduate and graduate students) have while translating state vectors in Dirac notation to wave functions in position and momentum representations, we administered free-response and multiple-choice questions and conducted individual interviews with students. We find that students display common difficulties with these topics.Quantum Physics/Foundations and Measurements/Hilbert Spacehttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13873Wed, 23 Dec 2015 19:40:09 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13873Developing and evaluating a tutorial on the double-slit experiment
http://www.thequantumexchange.org/items/detail.cfm?ID=13893
Learning quantum mechanics is challenging, even for upper-level undergraduate and graduate students. Interactive tutorials which build on students’ prior knowledge can be useful tools to enhance student learning. We have been investigating student difficulties with the quantum mechanics pertaining to the double-slit experiment in various situations. Here we discuss the development and evaluation of a Quantum Interactive Learning Tutorial (QuILT) which makes use of an interactive simulation to improve student understanding. We summarize common difficulties and discuss the extent to which the QuILT is effective in addressing them in two types of courses.Quantum Physics/Probability, Waves, and Interferencehttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13893Wed, 23 Dec 2015 19:24:41 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13893Investigating Student Understanding of Perturbation Theory and the Inner Products of Functions
http://www.thequantumexchange.org/items/detail.cfm?ID=13883
We have investigated the extent to which students can qualitatively determine the effect of perturbations to a Hamiltonian on the energies of the eigenfunctions. The results indicate that after lecture instruction many students cannot determine some important features of the first-order correction. We examine the possibility that this failure may stem from a lack of understanding of the inner product. Since perturbations are often represented graphically, the focus has been on student ability to determine the inner product of functions represented graphically. In the process, we have found that some students are unable to find inner products even in contexts outside of quantum mechanics.Quantum Physics/Foundations and Measurements/Hilbert Spacehttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13883Wed, 23 Dec 2015 17:16:06 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13883Investigating transfer of learning in advanced quantum mechanics
http://www.thequantumexchange.org/items/detail.cfm?ID=13872
Research suggests that students often have difficulty transferring their learning from one context to another. We examine upper-level undergraduate and graduate students’ facility with questions about the interference pattern in the double-slit experiment (DSE) with single photons and polarizers of various orientations placed in front of one or both slits. Before answering these types of questions, students had worked through a tutorial on the Mach-Zehnder Interferometer (MZI) in which they learned about interference of single photons when polarizers of various orientations are placed in the two paths of the MZI. After working on the MZI tutorial, students were asked similar questions in the isomorphic context of the DSE. We discuss the extent to which they were able to transfer what they learned in the context of the MZI to analogous problems in the isomorphic context of the DSE.Quantum Physics/Quantum Experimentshttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13872Wed, 23 Dec 2015 13:50:54 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13872SEI: Modern Physics - Quantum Learning Goals
http://www.thequantumexchange.org/items/detail.cfm?ID=13265
This page provides a list of learning goals for a PER-based Modern Physics Course. It includes expectations for student understanding of both specific topics and general concepts in quantum physics.
This is part of a resource collection covering an entire course.Quantum Physics/Generalhttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13265Sat, 21 Nov 2015 09:47:04 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13265Circular Well Model
http://www.thequantumexchange.org/items/detail.cfm?ID=9639
The Circular Well model displays the 2D energy eigenstates of a particle trapped in a very deep two-dimensional circular well. Because the Schrödinger equation for this system is separable into radial and angular differential equations, the solution can be expressed as a product of a Bessel function and and a complex exponential.
The Circular Well model is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_qm_CircularWell.jar file will run the program if Java is installed. You can modify this simulation if you have EJS installed by right-clicking within the plot and selecting “Open EJS Model” from the pop-up menu item.Quantum Physics/Bound State Systemshttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=9639Sat, 21 Nov 2015 09:46:24 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=9639Developing and Assessing Research-Based Tools for Teaching Quantum Mechanics and Thermodynamics
http://www.thequantumexchange.org/items/detail.cfm?ID=13786
Research-based tools to educate college students in physics courses from introductory level to graduate level are essential for helping students with a diverse set of goals and backgrounds learn physics. This thesis explores issues related to student common difficulties with some topics in undergraduate quantum mechanics and thermodynamics courses. Student difficulties in learning quantum mechanics and thermodynamics are investigated by administering written tests and surveys to many classes and conducting individual interviews with a subset of students outside the class to unpack the cognitive mechanisms of the difficulties. The quantum mechanics research also focuses on using the research on student difficulties for the development and evaluation of a Quantum Interactive Learning Tutorial (QuILT) to help students learn about the time-dependence of expectation values using the context of Larmor precession of spin and evaluating the role of asking students to self-diagnose their mistakes on midterm examination on their performance on subsequent problem solving. The QuILT on Larmor precession of spin has both paper-pencil activities and a simulation component to help students learn these foundational issues in quantum mechanics. Preliminary evaluations suggest that the QuILT, which strives to help students build a robust knowledge structure of time-dependence of expectation values in quantum mechanics using a guided approach, is successful in helping students learn these topics in the junior-senior level quantum mechanics courses. The technique to help upper-level students in quantum mechanics courses effectively engage in the process of learning from their mistakes is also found to be effective. In particular, research shows that the self-diagnosis activity in upper-level quantum mechanics significantly helps students who are struggling and this activity can reduce the gap between the high and low achieving students on subsequent problem solving. Finally, a survey oEducation Practices/Instructional Material Design/Tutorialhttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13786Sat, 21 Nov 2015 09:43:51 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13786Investigating Student Difficulties with Dirac Notation
http://www.thequantumexchange.org/items/detail.cfm?ID=13149
Quantum mechanics is challenging even for advanced undergraduate and graduate students. Dirac notation is a convenient notation used extensively in quantum mechanics. We have been investigating the difficulties that the advanced undergraduate and graduate students have with Dirac notation. We administered written free response and multiple-choice questions to students and also conducted semi-structured individual interviews with 23 students using a think-aloud protocol to obtain a better understanding of the rationale behind their responses. We find that many students struggle with Dirac notation and they are not consistent in using this notation across various questions in a given test. In particular, whether they answer questions involving Dirac notation correctly or not is context dependent.Quantum Physics/Foundations and Measurements/Hilbert Spacehttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13149Sat, 21 Nov 2015 09:42:40 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13149PER-Based Tutorials for Quantum Physics
http://www.thequantumexchange.org/items/detail.cfm?ID=13266
This series of student tutorials for quantum physics, covering topics of wave properties of light and matter, probability, and wave functions. Included with some of the tutorials are pre-tests for the topic and related homework.
This material is based on the work on Intuitive Quantum Physics from the University of Maryland, and tutorials developed at the University of WashingtonQuantum Physics/Probability, Waves, and Interferencehttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13266Sat, 21 Nov 2015 09:39:42 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13266Low-Cost Coincidence Counting Apparatus For Single Photon Optics Investigations
http://www.thequantumexchange.org/items/detail.cfm?ID=13806
We have recently started investigating single photon experiments for our advanced laboratory and quantum mechanics classes. For a small department, the expenses of much of the apparatus is daunting. As such, we look for places where we can reduce the costs while still providing benefits for our students. One of the places where there can be some cost savings are in the coincidence counting unit. The coincidence counting unit is a critical piece of the investigation, and while not the most expensive component, cost savings are still available. We have developed a low-cost coincidence counter (less than $50) based on a Cypress Programmable System on a Chip (PSoC). The PSoC is quite flexible and has both microcontroller as well as FPGA like capabilities which enable us to build the coincidence detection and the counter. The design process and several investigations will be presented.Quantum Physics/Quantum Experimentshttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13806Sat, 21 Nov 2015 09:38:09 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13806Advanced Laboratory Physics Association
http://www.thequantumexchange.org/items/detail.cfm?ID=13624
The Advanced Laboratory Physics Association (ALPhA) is an association of college and university faculty and staff dedicated to advanced experimental physics instruction. ALPhA works with other professional organizations, including the American Association of Physics Teachers (AAPT), the American Physical Society (APS), and the Optical Society of America (OSA), to advance laboratory instruction.
ALPhA's efforts include annual Laboratory Immersions Programs to help advanced laboratory instructors learn new labs, organizing conferences on advanced laboratories, and ALPhA’s relatively inexpensive Single Photon Detector Initiative.General Physics/Collections/Advanced Laboratorieshttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13624Sat, 21 Nov 2015 08:27:13 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13624Witnessing Entanglement
http://www.thequantumexchange.org/items/detail.cfm?ID=13795
An entangled state of a two-particle system is a quantum state that cannot be separated—it cannot be written as the product of states of the individual particles. One way to tell if a system is entangled is to use it to violate a Bell inequality (such as the Clauser-Horne-Shimony-Holt, CHSH, inequality), because entanglement is necessary to violate these inequalities. However, there are other, more efficient measurements that determine whether or not a system is entangled; an operator that corresponds to such a measurement is referred to as an entanglement witness. We present the theory of witness operators, and an undergraduate experiment that measures an entanglement witness for the joint polarization state of two photons. We are able to produce states for which the expectation value of the witness operator is entangled by more than 160 standard deviations.Quantum Physics/Entanglement and Quantum Informationhttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13795Thu, 19 Nov 2015 17:11:30 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13795The Quantum Mechanics of Two and Three Dimensional Nano-Structures
http://www.thequantumexchange.org/items/detail.cfm?ID=8662
Nano-science is one of the fastest growing fields in both physics and engineering. It is now possible to design and fabricate devices whose physical dimensions are on the nanometer scale and whose quantum properties can be tuned as desired. In this notebook we will study the quantum mechanics of what are known as reduced dimensional structures. A structure is said to have reduced dimensionality if one or more of the dimensions is on the order of the De Broglie wavelength of the particles confined to the structure. An ordinary wire for example, has no reduced dimensionality since both its length and its radius are large compared to the De Broglie wavelength of room temperature electrons.Quantum Physics/Bound State Systemshttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=8662Tue, 25 Aug 2015 10:49:04 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=8662Paradigms in Physics: Quantum Mechanics Activities
http://www.thequantumexchange.org/items/detail.cfm?ID=13622
This web page provides a list of learning activities for Junior level Quantum Mechanics classes. Each activity includes a description and learning goals, guides for instructors, handouts or worksheets, and reflections of instructors who have used the activity when available. Among the topics included are operators, time dependence, spin systems, and angular momentum. Links to related mathematical concepts are also provided.
This material is part of the Paradigms in Physics project at Oregon State University. This work promotes the use of active student learning in upper division physics courses. Both learning materials and learning strategies are provided to help both students and instructors.Quantum Physics/Generalhttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13622Wed, 24 Jun 2015 07:46:16 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13622Paradigms in Physics: Linear Combinations of Spherical Harmonics
http://www.thequantumexchange.org/items/detail.cfm?ID=13597
This computer visualization activity is designed to help upper division undergraduate students visualize linear combinations of spherical harmonics. Students use a Maple worksheet or Mathematica notebook to visualize various representations of probability densities of linear combinations of spherical harmonics. The entire class wrap-up discussion addresses how to represent linear combinations of spherical harmonics in a variety of ways.
This material is part of the Paradigms in Physics project at Oregon State University. This work promotes the use of active student learning in upper division physics courses. Both learning materials and learning strategies are provided to help both students and instructors.Mathematical Tools/Series and Functions/Spherical Harmonicshttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13597Mon, 22 Jun 2015 15:26:55 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13597Paradigms in Physics: Finding the Coefficients of a Spherical Harmonic Series
http://www.thequantumexchange.org/items/detail.cfm?ID=13598
This small group activity is designed to help upper division undergraduate students learn how to expand functions in terms of spherical harmonics. Students work in small groups to find the coefficients of a given function expanded in spherical harmonics. The whole class wrap-up discussion includes group presentations focusing on the notion that any function on the unit sphere can be expanded in terms of the orthonormal set of spherical harmonics.
This material is part of the Paradigms in Physics project at Oregon State University. This work promotes the use of active student learning in upper division physics courses. Both learning materials and learning strategies are provided to help both students and instructors.Mathematical Tools/Series and Functions/Spherical Harmonicshttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13598Mon, 22 Jun 2015 15:21:55 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13598QuILT Beta
http://www.thequantumexchange.org/items/detail.cfm?ID=13514
The QuILT Beta web site is a collection of pedagogical resources and activities for an upper-level undergraduate course in Quantum Mechanics. The materials include a series of concept tests covering all standard topics in the course and a series of interactive tutorials for active student learning. Several of the tutorials are combined with interactive simulations that promote student exploration. Pre- and Post-Tests, homework problems, and a concept survey are also included.Quantum Physics/Generalhttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13514Wed, 29 Apr 2015 18:33:44 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13514Developing a quantum mechanics concept inventory
http://www.thequantumexchange.org/items/detail.cfm?ID=13413
This paper describes the process of writing a quantum mechanics concept inventory concerning one-dimensional potential barriers, tunneling and probability distributions. It also explores some of the related alternative conceptions, and presents the results of 216 inventory questionnaires distributed to four groups of students.
One main result is that the question context is important for the models used when answering. The survey results show the alternative conceptions of energy loss due to tunneling and the view of a probability density peak as an indivisible entity are quite common (about 40 and 30 percent of the students, respectively).Quantum Physics/Probability, Waves, and Interferencehttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13413Mon, 23 Mar 2015 21:48:46 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13413Physlets Quantum Physics
http://www.thequantumexchange.org/items/detail.cfm?ID=13362
Physlet Quantum Physics 2E contains a collection of exercises about concepts from modern and quantum physics, facilitated by computer animations. Topics include special relativity, quantum experiments, quantum theory, and applications. Chapters are divided into Illustrations, Explorations, and Problems.
Illustrations are designed to demonstrate physical concepts. They are suitable for reading assignments prior to class and classroom demonstrations. Explorations are tutorial in nature. They provide hints or suggest problem-solving strategies to students in working problems and are useful as Just-in-Time Teaching exercises. Problems are interactive versions of the kind of exercises typically assigned for homework. They require the students to demonstrate their understanding, such as in homework assignments.Quantum Physics/Generalhttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13362Sat, 15 Nov 2014 00:59:54 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13362Tutorials in Physics: Quantum Mechanics
http://www.thequantumexchange.org/items/detail.cfm?ID=13267
This web site provides access to a set of student tutorials designed to supplement lectures and textbooks through in quantum mechanics. The tutorials are most suitable for courses in which there is an opportunity for students to work together in small groups; however, they can also be adapted for use in large, lecture hall settings. Carefully sequenced exercises and questions engage students in the type of active intellectual involvement that is necessary for developing a functional understanding of physics.
The website contains resources for instructors, including sample pretests, post-tests examination questions, suggestions for preparing Teaching Assistants, as well as details about the individual tutorials. Quantum Physics/Generalhttp://www.thequantumexchange.org/bulletinboard/Thread.cfm?ID=13267Fri, 06 Jun 2014 17:07:58 ESThttp://www.thequantumexchange.org/items/detail.cfm?ID=13267