- Open Access
Students’ difficulties with partial differential equations in quantum mechanics
Phys. Rev. Phys. Educ. Res. 16, 020163 – Published 21 December, 2020
DOI: https://doi.org/10.1103/PhysRevPhysEducRes.16.020163
Abstract
Upper-division physics students solve partial differential equations in various contexts in quantum mechanics courses. Separation of variables is a standard technique to solve these equations. We investigated students’ solutions to midterm exam questions and utilized think-aloud interviews. We also applied a framework that organizes students’ problem-solving process into four stages: activate, construct, execute, and reflect. Here we focused on students’ problem-solving process for two typical problems in the context of quantum mechanics: an energy eigenfunction problem in two spatial dimensions and a time evolution problem in one spatial dimension. We found that the students encountered various difficulties when they used the separation of variables technique to solve these partial differential equations. Common difficulties included recognizing when separation of variables is the appropriate method, deriving the correct separated equations from the original equation, deciding the signs of the separation constants, justifying when using the summation form of the wave function, and using an effective reflecting tool for their final solutions. In addition, we observed qualitatively and quantitatively different errors in students’ solutions to the two problems. Finally, we discussed the possible implications of our findings for instruction.
Physics Subject Headings (PhySH)
Article Text
References (55)
- C. Singh, Student understanding of quantum mechanics, Am. J. Phys. 69, 885 (2001).
- C. Singh, M. Belloni, and W. Christian, Improving students’ understanding of quantum mechanics, Phys. Today 59, No. 8, 43 (2006).
- C. Singh, Student understanding of quantum mechanics at the beginning of graduate instruction, Am. J. Phys. 76, 277 (2008).
- S. B. McKagan, K. K. Perkins, and C. E. Wieman, Deeper look at student learning of quantum mechanics: The case of tunneling, Phys. Rev. ST Phys. Educ. Res. 4, 020103 (2008).
- G. Zhu and C. Singh, Improving students’ understanding of quantum mechanics via Stern-Gerlach experiment, Am. J. Phys. 79, 499 (2011).
- G. Zhu and C. Singh, Surveying students’ understanding of quantum mechanics in one spatial dimension, Am. J. Phys. 80, 252 (2012).
- G. Zhu and C. Singh, Improving students’ understanding of quantum measurement I: Investigation of difficulties, Phys. Rev. ST Phys. Educ. Res., 8, 010117 (2012).
- G. Zhu and C. Singh, Improving students’ understanding of quantum measurement II: Development of Research-based learning tools, Phys. Rev. ST Phys. Educ. Res. 8, 010118 (2012).
- G. Zhu and C. Singh, Improving student understanding of addition of angular momentum in quantum mechanics, Phys. Rev. ST Phys. Educ. Res. 9, 010101 (2013).
- C. Singh and E. Marshman, Review of student difficulties in upper-level quantum mechanics, Phys. Rev. ST Phys. Educ. Res. 11, 020117 (2015).
- E. Marshman and C. Singh, Framework for understanding the patterns of student difficulties in quantum mechanics, Phys. Rev. ST Phys. Educ. Res. 11, 020119 (2015).
- G. Passante, P. J. Emigh, and P. S. Shaffer, Examining student ideas about energy measurements on quantum states across undergraduate and graduate levels, Phys. Rev. ST Phys. Educ. Res. 11, 020111 (2015).
- P. J. Emigh, G. Passante, and P. S. Shaffer, Student understanding of time dependence in quantum mechanics, Phys. Rev. ST Phys. Educ. Res. 11, 020112 (2015).
- E. Gire and E. Price, Structural features of algebraic quantum notations, Phys. Rev. ST Phys. Educ. Res. 11, 020109 (2015).
- C. Baily and D. N. Finkelstein, Teaching quantum interpretations: Revisiting the goals and practices of introductory quantum physics, Phys. Rev. ST Phys. Educ. Res. 11, 020124 (2015).
- K. Krijtenburg-Lewerissa, H. J. Pol, A. Brinkman, and W. R. van Joolingen, Insights into teaching quantum mechanics in secondary and lower undergraduate education, Phys. Rev. Phys. Educ. Res. 13, 010109 (2017).
- E. Marshman and C. Singh, Investigating and improving student understanding of quantum mechanics in the context of single photon interference, Phys. Rev. Phys. Educ. Res. 13, 010117 (2017).
- R. Sayer, A. Maries, and C. Singh, Quantum interactive learning tutorial on the double-slit experiment to improve student understanding of quantum mechanics, Phys. Rev. Phys. Educ. Res. 13, 010123 (2017).
- A. Maries, R. Sayer, and C. Singh, Effectiveness of interactive tutorials in promoting “which-path” information reasoning in advanced quantum mechanics, Phys. Rev. Phys. Educ. Res. 13, 020115 (2017).
- J. R. Hoehn and N. D. Finkelstein, Students’ flexible use of ontologies and the value of tentative reasoning: Examples of conceptual understanding in three canonical topics of quantum mechanics, Phys. Rev. Phys. Educ. Res. 14, 010122 (2018).
- P. J. Emigh, G. Passante, and P. S. Shaffer, Developing and assessing tutorials for quantum mechanics: Time dependence and measurements, Phys. Rev. Phys. Educ. Res. 14, 020128 (2018).
- T. Wan, P. J. Emigh, and P. S. Shaffer, Investigating how students relate inner products and quantum probabilities, Phys. Rev. Phys. Educ. Res. 15, 010117 (2019).
- T. Wan, P. J. Emigh, and P. S. Shaffer, Probing student reasoning in relating relative phase and quantum phenomena, Phys. Rev. Phys. Educ. Res. 15, 020139 (2019).
- C. D. Porter and A. F. Heckler, Graduate student misunderstandings of wave functions in an asymmetric well, Phys. Rev. Phys. Educ. Res. 15, 010139 (2019).
- B. P. Schermerhorn, G. Passante, H. Sadaghiani, and S. J. Pollock, Exploring student preferences when calculating expectation values using a computational features framework, Phys. Rev. Phys. Educ. Res. 15, 020144 (2019).
- G. Passante and A. Kohnle, Enhancing student visual understanding of the time evolution of quantum systems, Phys. Rev. Phys. Educ. Res. 15, 010110 (2019).
- B. Modir, J. D. Thompson, and E. C. Sayre, Framing difficulties in quantum mechanics, Phys. Rev. Phys. Educ. Res. 15, 020146 (2019).
- S. Y. Lin and C. Singh, Categorization of quantum mechanics problems by professors and students, Eur. J. Phys. 31, 57 (2010).
- B. Modir, J. D. Thompson, and E. C. Sayre, Students’ epistemological framing in quantum mechanics problem solving, Phys. Rev. Phys. Educ. Res. 13, 020108 (2017).
- C. L. Rasmussen and K. D. King, Locating starting points in differential equations: A realistic mathematics education approach, Int. J. Math. Educ. Sci. Technol. 31, 161 (2000).
- S. Habre, Exploring students’ strategies to solve ordinary differential equations in a reformed setting, J. Math. Behav. 18, 455 (2000).
- C. L. Rasmussen, New directions in differential equations: A framework for interpreting students’ understandings and difficulties, J. Math. Behav. 20, 55 (2001).
- B. R. Wilcox and S. J. Pollock, Upper-division student difficulties with separation of variables., Phys. Rev. ST Phys. Educ. Res. 11, 020131 (2015).
- B. R. Wilcox, M. D. Caballero, D. A. Rehn, and S. J. Pollock, Analytic framework for students’ use of mathematics in upper-division physics, Phys. Rev. ST Phys. Educ. Res. 9, 020119 (2013).
- B. R. Wilcox and S. J. Pollock, Upper-division student difficulties with the Dirac delta function, Phys. Rev. ST Phys. Educ. Res. 11, 010108 (2015).
- Q. X. Ryan, B. R. Wilcox, and S. J. Pollock, Student difficulties with boundary conditions in the context of electromagnetic waves, Phys. Rev. ST Phys. Educ. Res. 14, 020126 (2018).
- J. P. Zwolak and C. A. Manogue, Assessing student reasoning in upper-division electricity and magnetism at oregon state university, Phys. Rev. ST Phys. Educ. Res. 11, 020125 (2015).
- M. E. Loverude and B. S. Ambrose, Editorial: Focused collection: PER in upper-division physics courses., Phys. Rev. ST Phys. Educ. Res. 11, 020002 (2015).
- E. C. Sayre and M. C. Wittmann, Plasticity of intermediate mechanics students’ coordinate system choice, Phys. Rev. ST Phys. Educ. Res. 4, 020105 (2008).
- C. S. Wallace and S. V. Chasteen, Upper-division students’ difficulties with Ampere’s law, Phys. Rev. ST Phys. Educ. Res. 6, 020115 (2010).
- D.-H. Nguyen and N. S. Rebello, Students’ difficulties with integration in electricity, Phys. Rev. ST Phys. Educ. Res. 7, 010113 (2011).
- R. E. Pepper, S. V. Chasteen, S. J. Pollock, and K. K. Perkins, Observations on student difficulties with mathematics in upper-division electricity and magnetism, Phys. Rev. ST Phys. Educ. Res. 8, 010111 (2012).
- E. B. Pollock, J. R. Thompson, and D. B. Mountcastle, Student understanding of the physics and mathematics of process variables in P-V diagrams, AIP Conf. Proc. 951, 168 (2007).
- M. E. Loverude, Student understanding of basic probability concepts in an upper-division thermal physics course, AIP Conf. Proc. 1179, 189 (2009).
- M. E. Loverude, Investigating student understanding for a statistical analysis of two thermally interacting solids, AIP Conf. Proc. 1289, 213 (2010).
- T. I. Smith, J. R. Thompson, and D. B. Mountcastle, Student understanding of Taylor series expansions in statistical mechanics, Phys. Rev. ST Phys. Educ. Res. 9, 020110 (2013).
- T. J. Bing and E. F. Redish, Analyzing problem solving using math in physics: Epistemological framing via warrants, Phys. Rev. ST Phys. Educ. Res. 5, 020108 (2009).
- R. R. Bajracharya, P. J. Emigh, and C. A. Manogue, Students’ strategies for solving a multirepresentational partial derivative problem in thermodynamics, Phys. Rev. Phys. Educ. Res. 15, 020124 (2019).
- M. D. Caballero, B. R. Wilcox, L. Doughty, and S. J. Pollock, Unpacking students’ use of mathematics in upper-division physics, Eur. J. Phys. 36, 065004 (2015).
- J. Y. Zeng, Quantum Mechanics (Science Press, Beijing, 2008).
- D. J. Griffiths, Introduction to Quantum Mechanics (Pearson Prentice Hall, New Jersey, 2004).
- M. T. H. Chi, in The Thinking Aloud Method, edited by M. W. van Someren, Y. F. Barnard, and J. A. C. Sandberg (Academic Press, London, 1994), Chap. 1.
- S. K. Reed, G. W. Ernst, and R. Banerji, The role of analogy in transfer between similar problem states, Cogn. Psychol. 6, 436 (1974).
- T. D. Tomlinson, D. E. Huber, C. A. Rieth, and E. J. Davelaar, An interference account of cue-independent forgetting in the no-think paradigm, Proc. Natl. Acad. Sci. U.S.A. 106, 15588 (2009).
- B. W. Frank, S. E. Kanim, and L. S. Gomez, Accounting for variability in student responses to motion questions, Phys. Rev. ST Phys. Educ. Res. 4, 020102 (2008).