Abstract Quantum mechanics (QM) is one of the core subject areas in the undergraduate physics curriculum and many of the advanced level physics courses involve direct or indirect application of the concepts and ideas taught in QM. On the other hand, proper understanding of QM interpretations requires an optimum level of understanding of fundamental concepts in classical physics such as energy, momentum, force and their role in determining motion of the particle. This study is an attempt to explore a group of undergraduate students’ mental models regarding fundamental concepts in classical physics which are actually the stepping stone for understanding and visualisation of QM. The data and analysis presented here elucidate the challenges students face to understand the classical ideas and how that affects their understanding of QM.
Abstract Quantum mechanics (QM) is one of the core subject areas in the undergraduate physics curriculum and many of the advanced level physics courses involve direct or indirect application of the concepts and ideas taught in QM. On the other hand, proper understanding of QM interpretations requires an optimum level of understanding of fundamental concepts in classical physics such as energy, momentum, force and their role in determining motion of the particle. This study is an attempt to explore a group of undergraduate students’ mental models regarding fundamental concepts in classical physics which are actually the stepping stone for understanding and visualisation of QM. The data and analysis presented here elucidate the challenges students face to understand the classical ideas and how that affects their understanding of QM.
Abstract Quantum mechanics (QM) forms the most crucial ingredient of modern-era physical science curricula at undergraduate level. The abstract ideas involved in QM related concepts pose a challenge towards appropriate visualization as a consequence of their counter-intuitive nature and lack of experiment-assisted visualization tools. At the heart of the quantum mechanical formulation lies the concept of ‘wavefunction’, which forms the basis for understanding the behavior of physical systems. At undergraduate level, the concept of ‘wavefunction’ is introduced in an abstract framework using mathematical tools and therefore opens up an enormous scope for alternative conceptions and erroneous visualization. The present work is an attempt towards exploring the visualization models constructed by undergraduate students for appreciating the concept of ‘wavefunction’. We present a qualitative analysis of the data obtained from administering a questionnaire containing four visualization based questions on the topic of ‘wavefunction’ to a group of ten undergraduate-level students at an institute in India which excels in teaching and research of basic sciences. Based on the written responses, all ten students were interviewed in detail to unravel the exact areas of difficulty in visualization of ‘wavefunction’. The outcome of present study not only reveals the gray areas in students’ conceptualization, but also provides a plausible route to address the issues at the pedagogical level within the classroom.
Not only is Quantum Mechanics (QM) conceptually rich, it is also a theory that physics students have found abstract and technically formidable. Nevertheless, compared to other classical topics of physics, university students’ understanding of QM has received minimal attention in the physics education literature. The principal purpose of this study was to characterize the variation in the ways that undergraduate physics students depict the basic concepts of QM and to extrapolate the results to scaffold possible changes to instructional practices at the university that provided the context for the study. In so doing, an adaptation of a developmental phenomenographic perspective was chosen. Empirically, the study was approached through in-depth interviews with 35 physics students from two Ethiopian governmental universities after they had been exposed to the traditional QM course for one-third of a semester. Interview responses were analyzed using phenomenographic approach where a picture of students’ depictions was established for each quantum concept by expounding the given responses. For each basic quantum concept addressed, the structure of the description categories was separately constructed, and overall, it was found that naive, quasi-classical ontology and/or variants of classical ways of visualization are dominant in students’ responses. For example, it was found that students’ depictions of the photon concept could be described with three distinct categories of description, which are (a) classical intuitive description, (b) mixed model description and (c) quasi-quantum model description. Similarly, the findings revealed that it is possible to establish three qualitatively different categories of description to picture students’ depictions of matter waves, namely, (a) classical and trajectory-based description, (b) an intricate blend of classical and quantum description and (c) incipient quantum model description. Likewise, it was found that students’ depictions of uncertainty principle can be described as: (a) uncertainty as classical ignorance, (b) uncertainty as measurement disturbance and (c) uncertainty as a quasi-quantum principle. \nWith regard to learning QM, the categories of description made clear several issues: most students did not have enough knowledge to depict the basic concepts of QM properly; they were influenced by the perspective of classical physics and their perceptions in making explanations about QM; and they also applied mixed ideas, one based on their classical model and the other from newly introduced QM. These results are also supported by the findings of previous studies in similar domains. Findings from the study were used to guide the design of multiple representations-based instructions and interactive learning tutorials on the conceptual aspects of QM that has been shown to address specific difficulties identified in the study. Theoretical and practical implications of the study, as well as potential future considerations are drawn.
Quantum mechanics is generally an abstract theory that challenges intuition since it cannot be understood using ordinary experiences. Quantum tunneling is one of the topics which is more counterintuitive and challenges students' conceptual understanding. The study was aimed at investigating if final year undergraduate quantum mechanics students have alternative conceptions regarding quantum tunneling phenomena after a full course of instruction. In this study, students’ alternative conceptions are referred to as any student ideas related to the incorrect belief of scientific principles. Using the deep structured interviews involving 36 students who were registered in a quantum physics course from the University of Malawi, we found that some students hold on to the idea that the energy of a quantum tunneling electron is lost, the wave function graph depicts the physical wave, and the “potential step,” and “barrier” means a physical object/barrier. The study further established that the possible sources of these alternative conceptions emanated from students’ experience with classical tunneling / classical mechanics, quantum mechanics lecturer notes, and previous quantum mechanics lessons. The findings of this study further portray that traditional pedagogy has its limitation in facilitating students' comprehension of quantum tunneling. We recommend that further research into the design of instructional technology for quantum physics should consider these students' alternative conceptions when designing visual, interactive, and mental models, which may help establish students' conceptual understanding of quantum mechanics.
This study aimed at investigating the problems students face in understanding the concepts of angular momentum in classical and quantum mechanics, finding an effective way of improving understanding and learning the concepts of angular momentum in quantum mechanics, lastly document the challenges investigated and suggest some solutions to help students understand angular momentum in both classical and quantum mechanics. This study summarizes a series of investigations into how undergraduate Physics students perceive angular momentum in quantum mechanics at the University of Zambia. We investigated undergraduate physics student's perception of angular momentum in quantum mechanics by administering written questions (open-ended) to two different groups of classes. Out of these investigations we developed a Quantum Interactive Learning Tutorials (Qu I L Ts) and peer instruction tools to assist the students build up a considerable knowledge structure of quantum mechanics in general and angular momentum in specific, through a guided approach technique [1]. Eleven questions were administered to a group of N = 15 students, statistics for answered questions are as follows; question one 4 out of 15 representing a percentage of 26.67%, question two only 6 out of 15 student representing 40%, question three 11 out of 15 representing a percentage of 73.33%, for question four only 1 out of 15 representing a percentage of 6.67%, question five none of the students answered, question six only 1 out of 15 students representing a percentage of 6.67% managed to answer, question seven 1 out of 15 representing a percentage of 6.67% managed to answer, question eight 11 out of 15 representing a percentage of 73.33 % got the correct answer, question nine 6 out of 15 representing a percentage 40% got the right answer, question ten only three students making a percentage of 20% answered correctly, question eleven no student managed to get it right. Preliminary results show that the undergraduate physics students perception of quantum mechanics is improved after using the research-based learning tools in the lower class level quantum mechanics courses [1]. We also build up a common conceptual survey that can help lecturers better investigate undergraduate physics students understand the concept of angular momentum in particular and quantum mechanics courses in general.
The physics education research (PER) literature on quantum mechanics (QM) often acknowledges and minimizes what we refer to as the enigma of QM, viewing these aspects of QM as a challenge to overcome, rather than an inherent feature to be leveraged for learning. Using the overlapping theories of knowledge-in-pieces and resource theory as connected to an epistemological framing perspective, we focus on students’ descriptions of the enigma of QM and the epistemological frames that students view as relevant when approaching QM. Data comes from interviews with 10 undergraduate physics students who had learned quantum physics topics across different courses in the curriculum, ranging from sophomore-level modern physics to an advanced undergraduate-level QM course. To elicit students’ ideas on QM, the interview protocol emphasized their perspectives and empowerment when possible. Iterative rounds of qualitative analysis coded the data for how students described enigmatic aspects of QM, along with three epistemological frames students identified as their reasoning strategies: reasoning about scale, reasoning about the connections between QM and mathematics, and reasoning about the connections between QM and classical mechanics. The results document that students are aware that something about QM is unexplainable, an enigma to acknowledge. We argue that acknowledgment of the enigma of QM is a key part of what we refer to as thinking quantumly. Additionally, the epistemological frame of reasoning about scale has not been widely discussed in the QM-PER literature, which students use to distinguish QM from classical mechanics and to explain why mathematical models are needed. These results are important for amplifying students’ voices in how they approach enigmatic aspects of QM. Thus, our results begin to move the QM-PER literature beyond viewing enigmatic aspects of QM as obstacles to be corrected through refined instruction, toward an asset-based orientation as a source of meaningful insights for the learning process.
This paper is part of the Focused Collection on Upper Division Physics Courses.]Energy measurements play a fundamental role in the theory of quantum mechanics, yet there is evidence that the underlying concepts are difficult for many students, even after all undergraduate instruction.We present results from an investigation into student ability to determine the possible energies that can be measured for a given wave function and Hamiltonian, to determine the probabilities of each energy measurement and how they depend on time, and to recognize how a measurement of energy affects the state.By analyzing student responses to open-ended questions, we identify five broad, interrelated sets of conceptual and reasoning difficulties related to energy measurements.Data are drawn from sophomore-, junior-, and graduate-level quantum mechanics courses.Particular attention is paid to incorrect ideas that persist across all levels.