O experimento da borracha quântica: discutindo o quântico pelo clássico em sala de aula

The present work is directed to the Basic Education teacher, but it can also serve the interests of Initial and Continuing Teacher Education, and proposes an activity covering two fields that require more attention in current Physics Teaching: the insertion of Modern and Contemporary Physics topics at High School, and the proposition of new experimental activities to that segment of Basic Education. The experiment called "quantum eraser" addresses, qualitatively, some of the fundamental principles of Quantum Mechanics.  The experiment is composed of a laser and some polarizing filters, obtained from the screen of used digital displays, such as calculators and multimeters, and allows contextualization and discussion of the quantum concepts of wave function, quantum states, superposition of states, probability, state determination and collapse of the wave function, according to the Copenhagen School interpretation. The proposed concepts, based on the postulates of Quantum Mechanics, were subject to a didactic transposition process, to adapt to the cognitive level of high school students. The experimental apparatus is easy to build using low-cost materials, making it possible to explore it in the classroom by the teacher. The results obtained experimentally were considered of good quality and consistent with expectations, when the experiment was applied to high school students.