Investigating Students' Understanding of Quantum Measurement

As quantum measurement is a fundamental concept in any student's preparation for Quantum Information Science, it is a major concept of focus for upper-division quantum mechanics courses. This is particularly true for a massive open online course hosted on EdX and offered through Georgetown University, both in-person and fully online, where the course focuses on a series of quantum mechanical concepts and modern quantum experiments. Our research analyzes a series of student responses to multiple-choice, short-answer, and essay responses throughout the course with this talk focusing on items that discuss various aspects of quantum measurement. We will discuss our preliminary findings on students' ideas associated with measurement in the Stern-Gerlach experiment and the Mach-Zehnder Interferometer, and students' progression with these topics throughout the course. For example, we have observed that students often attempt to reason mechanistically about the behavior of atoms passing through analyzer loops in the Stern-Gerlach experiment, leading them to assign agency to an atom to 'choose' its path through a loop.