Formal and informal approaches to quantum mechanics using quantum cryptography

Abstract

Quantum technologies rely on superposition and entanglement, concepts that challenge classical physics and provide a rich context for teaching. In this paper, we report on a course for high school teachers that focused on quantum cryptography, one of the most mature quantum technologies. The course aims to provide teachers with an innovative approach to introducing quantum physics at the high-school level, showcasing quantum cryptography as a compelling example of how modern technology exploits fundamental principles of quantum theory. The course covers quantum mechanics, light polarization, and the BB84 quantum key distribution protocol through theoretical and experimental sessions by integrating formal and informal approaches exploiting lectures, online simulations (QuVis) and hands-on laboratory activities (using Thorlabs Quantum Cryptography Demonstration Kit). In addition, a card game, originally developed as a public outreach tool, was introduced to interactively perform the BB84 protocol. Feedback from teachers confirmed the feasibility of integrating these concepts into curricula to promote quantum literacy and engagement in secondary education.