Investigating student interpretations of the differences between classical and quantum computers: Are quantum computers just analog classical computers?

TL;DR

This study explores how students interpret the differences between classical and quantum computers, revealing misconceptions and highlighting effective teaching strategies to improve understanding in interdisciplinary quantum information science courses.

Contribution

It provides insights into student reasoning about classical versus quantum computers and demonstrates the effectiveness of analog classical computer thought experiments in education.

Findings

Students often confuse exponential and linear scaling effects.

Analog classical computer thought experiments aid understanding.

Students tend to focus on analog-digital distinctions over classical-quantum.

Abstract

Significant attention in the PER community has been paid to student cognition and reasoning processes in undergraduate quantum mechanics. Until recently, however, these same topics have remained largely unexplored in the context of emerging interdisciplinary quantum information science (QIS) courses. We conducted exploratory interviews with 22 students in an upper-division quantum computing course at a large R1 university crosslisted in physics and computer science, as well as 6 graduate students in a similar graduate-level QIS course offered in physics. We classify and analyze students' responses to a pair of questions regarding the fundamental differences between classical and quantum computers. We specifically note two key themes of importance to educators: (1) when reasoning about computational power, students often struggled to distinguish between the relative effects of exponential and linear scaling, resulting in students frequently focusing on distinctions that are arguably better understood as analog-digital than classical-quantum, and (2) introducing the thought experiment of analog classical computers was a powerful tool for helping students develop a more expertlike perspective on the differences between classical and quantum computers.