Wave-particle duality and uncertainty principle: Phenomenographic categories of description of tertiary physics students' depictions.

Abstract

Quantum mechanics is often thought to be a difficult subject to understand, not only in the complexity of its mathematics, but also in its conceptual foundation. In this paper we emphasise students’ depictions of the uncertainty principle and wave-particle duality of quantum events, phenomena that could serve as a foundation in building an understanding of quantum mechanics. A phenomenographic study was carried out to categorise a picture of students’ descriptions of these key quantum concepts. Data for this study were obtained from a semi-structured in-depth interview conducted with undergraduate physics students (N = 25) from Ethiopia. The phenomenographic data analysis revealed that it is possible to construct three qualitatively different categories to map students’ depictions of the concept wave-particle duality, namely: (1) Classical description; (2) Mixed Classical-Quantum description; and (3) Quasi-Quantum description. Similarly, it is proposed that students’ depictions of the concept uncertainty can be described with four different categories of description, which are: (1) uncertainty as extrinsic property of measurement; (2) uncertainty principle as measurement error/uncertainty; (3) uncertainty as measurement disturbance; and (4) uncertainty as quantum mechanics uncertainty principle. Overall, we found students are more likely to prefer a classical picture of interpretations of quantum mechanics. However, few students in the quasi-quantum category applied typical wave phenomena such as interference and diffraction that cannot be explained within the framework classical physics for depicting the wave-like properties of quantum entities. Despite students' conceptions of the uncertainty principle and wave- and particle-like properties of quantum entities are severely inhospitable in our investigation, the findings presented in this paper are highly consistent with those reported in previous studies. New findings and some implications for instruction and the curricula are discussed.