The recent and rapid progress in the field of quantum technologies stimulates developments of specific courses and experimental training for future engineers and scientists. We describe below the experimental setup developed at Institut d’Optique Graduate School for engineering and Master students. During a labwork session afternoon, students can study a source of polarization entangled state pairs of photons and perform an experimental violation of Bell’s inequalities. This emblematic experiment is one of the experiments dedicated to quantum photonics. It was built in 2005 in the LEnsE (the Laboratoire d’Enseignement Experimental) of the Institut d’Optique Graduate School and has been perfectly working for almost eighteen years already.
The recent and rapid progress in the field of quantum technologies stimulates developments of specific courses and experimental training for future engineers and scientists. We describe below the experimental setup developed at Institut d’Optique Graduate School for engineering and Master students. During a labwork session afternoon, students can study a source of polarization entangled state pairs of photons and perform an experimental violation of Bell’s inequalities. This emblematic experiment is one of the experiments dedicated to quantum photonics. It was built in 2005 in the LEnsE (the Laboratoire d’Enseignement Experimental) of the Institut d’Optique Graduate School and has been perfectly working for almost eighteen years already.
Abstract This paper presents a new lab work concept promoting a series of quantum optics experiments: experimental milestones on the quantum behaviour of light designed for undergraduate lab work. The experiments may be carried out with considerably less effort while addressing the fundamentals of quantum theory: quantum states and their superposition, detected via the propagation phase of probability amplitudes; quantum nonlocality, detected via the change of the state due to localized detection; quantum entanglement , detected via the violation of Bell ’s inequality (CHSH criterion). The experimental setup is designed to meet the requirements of barrier-free multilevel use in undergraduate physics lab courses: students’ labs for secondary school students, undergraduate university labs for physics students (science and science education) and lab work assisted courses for the training of in-service physics teachers. This article is aimed to describe the basics of the setup and to show how the experiments may be implemented into lab courses to match different educational course levels. The experimental series could prove to be promising in terms of fruitful discussion of quantum theory fundamentals without semiclassical pitfalls.
Teaching quantum mechanics at the secondary school level remains a major educational challenge. Traditional historical approaches often present the theory as a sequence of disconnected phenomena, requiring extensive prior knowledge of classical physics before students can appreciate the conceptual structure of quantum physics. In this work, we present the design, implementation, and evaluation of a curriculum based on the two state (qubit first) approach, in which the fundamental postulates of quantum mechanics are introduced through mathematically accessible two level systems and realized with light polarization. The curriculum integrates theoretical instruction, laboratory activities, a coherent progression grounded in the interactive simulations, and inquiry based learning into a coherent pathway that progresses from quantum states and superposition to entanglement and the experimental violation of Bell's inequalities. A distinctive feature of the project is the experimental realization of the violation of Bell's inequalities obtained in a newly established quantum optics laboratory in an Italian high school, where students performed, for the first time in Italy, an authentic Bell test using polarization-entangled photons. The same educational framework was adopted for in service teacher professional development courses. Learning outcomes were evaluated through mixed methods. Preliminary analysis indicates significant improvements in conceptual understanding, confidence in using mathematical formalism, and appreciation of the relationship between theory, experimentation, and the foundations of quantum mechanics. The proposed curriculum shows that two-state formalism and supported by real laboratory experiences enables secondary-school students to engage more meaningfully with both the conceptual foundations of quantum mechanics and their experimental verification.
In 1964, J. Bell introduced an inequality that stated a mathematical bound for any physical system that holds both locality and realism; if we violate this inequality, it is clear that we have to reconsider the previous statement. In our work, we report an experimental activity with photons suitable for undergraduate students that makes them question these naïve ideas of nature’s behavior. With a pre-aligned setup, our students tested and violated Bell’s inequality in a two-hour laboratory session, using two distant photons entangled in polarization. In addition, complementing an educational approach to this phenomenon, the usually called S function, that quantifies correlations, was mapped using different detection angles in one of the two locations. In particular, a more complete picture of the S function, allow us to identify the initial state of light. We show in this work that it is possible for undergraduate students to question some of our common sense ideas of nature using experiments with photons.
Abstract A laboratory experiment and related computational activities for advanced undergraduate or introductory graduate students on quantum entanglement are developed and described. Students characterize the quality of entanglement of a system, use code to predict the best experimental parameters for the system, and then perform a modified Bell measurement. The results can show non-classical behavior for any (non-zero) level of entanglement. Demonstration of the experiment on an IBM quantum computer is also shown, including the additional effects of decoherence on such a system. While a potentially interesting experiment for any program, it can open new avenues of education particularly for smaller colleges and universities on a more limited budget.
Recently, an experiment was done in the realm of Quantum Information that won the recent 2022 Nobel prize in Physics. This experiment breaks Bell's inequality, supporting quantum theory over hidden variable theory—the research done is considered one of the pioneering experiments for quantum information science. This research paper documented the theory of the experiment done and experimentally tested for the violation of Bell's inequality, using materials similar to the experiments from the past, in an attempt to provide more support for quantum information. Through repetition of the experiment, it was simple to brainstorm more potential experimentation and design that will further develop entanglement. The mathematical formulation and terms are the same as defined in past works in detail in order to keep notation and inequalities constant throughout the analysis. Using the data points and error propagation, I have shown that Bell's inequality is violated to a great extent. This paper finally addresses potential experimentation regarding quantum entanglement and its applications to quantum sensors and computing technology.
Experiments testing Bell's inequalities generally uses sources of entangled photons emitted in opposite direction, sent through polarizer of specific different orientation and finally correlated. But the correlation result would be the same if photons was emitted by only one source of 360° rotating polarization, separated in two flux by a semi-transparent mirror, and finally correlated as in the standard experiment. Therefore, it would demonstrate that the result is not due to any entangled state of the photons.