Implementation and goals of quantum optics experiments in undergraduate instructional labs

As quantum information science and technology (QIST) is becoming more prevalent and occurring not only in research labs but also in industry, many educators are considering how best to incorporate learning about quantum mechanics into various levels of education. Although much of the focus has been on quantum concepts in nonlab courses, current work in QIST has a substantial experimental component. Many instructors of undergraduate lab courses want to provide their students the opportunity to work with quantum experiments. One common way this is done is through a sequence of quantum optics experiments often referred to as the “single-photon experiments.” These experiments demonstrate fundamental quantum phenomena with equipment common to research labs; however, they are resource intensive and cannot be afforded by all institutions. It is therefore imperative to know what unique affordances these experiments provide to students. As a starting point, we surveyed and interviewed instructors who use the single-photon experiments in undergraduate courses, asking how and why they use the experiments. We describe the most commonly used experiments in both quantum and beyond-first-year lab courses, the prevalence of actions the students perform, and the learning goals, ranging from conceptual knowledge to lab skills to student affect. Finally, we present some strategies from these data demonstrating how instructors have addressed the common challenges of preparing students to work with conceptually and technically complex experiments and balancing the practice of technical skills with the completion of the experiments.

Figure 1

The (a) schematic of the experiment and (b) photo of an actual experiment for the single-photon interferometer.

Figure 2

(a) Number of experiments used per course ($N=37$). (b) Fraction of all courses (red, $N=37$), quantum courses (orange, $N=8$), and BFY lab courses (yellow, $N=25$) in which each of the different experiments was used, sorted by the fraction of all courses.

Figure 3

Actions students performed. On the left is shown the fraction of all (red, $N=37$), quantum (orange, $N=8$), and BFY lab (yellow, $N=25$) courses in which students performed the specific action in at least one of the experiments. On the right, with the same vertical axis, is shown the fraction of courses that perform the experiments SPDC ($N=18$, darkest blue), existence of a photon ($N=20$), single-photon interferometer ($N=24$), quantum eraser ($N=14$), and Bell’s inequality ($N=21$, lightest green) in which the students performed the specific action.

Figure 4

(a) Percent of courses in which the instructor marked very important (dark blue), somewhat important (light blue), and not important (gray) as the highest level of importance for the given goal over all experiments used in their course. Due to a few missing responses, the number of courses $N=34$ for the goal of learning concepts about quantum states, $N=36$ for the goal of learning concepts about the wavelike nature of particles, and $N=37$ for all other goals. (b) Percent of courses using each experiment in which the instructor ranked each goal as very important (dark blue), somewhat important (light blue), and not important (gray) for the five most common experiments (distinguished by hatching). The goals are sorted by the average percentage of very important rankings over the five experiments.