Quantum Optics 2 - Two photons and more from Coursera

"Quantum Optics 1, Single photons", allowed learners to be introduced to the basic principles of light quantization, and to the standard formalism of Quantum Optics. All the examples were taken in single photons phenomena, including applications to quantum technologies.

In the same spirit, "Quantum Optics 2, Two photons and more", will allow learners to use the Quantum Optics formalism to describe entangled photon, a unique feature at the root of the second quantum revolution and its applications to quantum technologies. Learners will also discover how the Quantum Optics formalism allows one to describe classical light, either coherent such as laser light, or incoherent such as thermal radiation. Using a many photons description, it is possible to derive the so-called Standard Quantum Limit (SQL), which applies to classical light, and to understand how new kinds of quantum states of light, such as squeezed states of light, allow one to beat the SQL, one of the achievements of quantum metrology. Several examples of Quantum Technologies based on entangled photons will be presented, firstly in quantum communication, in particular Quantum Teleportation and Quantum Cryptography. Quantum Computing and Quantum Simulation will also be presented, including some insights into the recently proposed Noisy Intermediate Scale Quantum (NISQ) computing, which raises a serious hope to demonstrate, in a near future, the actively searched quantum advantage, ie, the possibility to effect calculations exponentially faster than with classical computers.

What's inside

Syllabus

QUASI-CLASSICAL STATES OF RADIATION: SINGLE MODE CASE

In this lesson you will discover the formalism of quasi-classical states of radiation. Introduced by Roy Glauber in the early 1960's, it has allowed one to fill the gap between the notion of photon, at the heart of quantum optics, and the fundamental property of light considered as a classical field, its coherence. You will understand why the classical model of light is so successful. You will also understand what is the shot noise, and the associated Standard Quantum Limit (SQL). It will allow you to better appreciate, in future lessons, the possibility to pass that Standard Quantum Limit, which was considered for a long time an ultimate limit.

MULTIMODE QUASI-CLASSICAL STATES OF RADIATION

In this lesson you will learn how to use multimode quasi-classical states of light to describe real classical light, with several components. You will find the demonstration of the behaviour of a quasi-classical wave packet on a beam-splitter, a property used in quantum optics 1 to show the dramatic difference between a classical and a single photon wave packet. You will also learn how to describe in quantum optics the observation of a beatnote between two lasers. This is an interesting subject in itself, which raised many discussions in the years following the invention of lasers, and which is crystal clear when discussed as in this lesson. It is also a much used technique in AMO laboratories, known a heterodyne detection, of which you will learn the interest and the limits. You will also encounter some fundamental ideas about incoherent vs coherent muitimode radiation, and about similarities and differences between a classical statistical average and a quantum average. With these notions, you will be armed to better appreciate specific quantum properties of squeezed light, presented in the next lesson.

SQUEEZED LIGHT: BEATING THE STANDARD QUANTUM LIMIT

In this lesson, you will learn about non-classcal states of light, squeezed states, which allow one to "beat the Standard Quantum Limit", ie, to realize measurements with an uncertainty smaller than what was considered the ultimate limit, which in fact applies to a perfectly controlled classical beam of light, either a laser beam or a beam from a standard source. The notion of squeezed states of light was discovered in 1980, in the hope to succeed in detecting gravitational waves with giant optical interferometers. Almost 40 years later, Squeezed States of Light are effectively used with these giant interferometers, and they promise to increase significantly the volume of the universe explored by these interferometers. This is an example of a quantum technology based on a multi-photons quantum state, without any classical equivalent.

ENTANGLEMENT: A REVOLUTIONARY CONCEPT

Entanglement is a quantum mechanical feature which was ignored or underestimated for a long time, in spite of the debate between Einstein and Bohr about it. It is only with John Bell's discovery, in the mid 1960's, that one could experimentally settle the debate, that some physicists realized the possibility to use entanglement for new ways of processing and transmitting information. In this lesson, you will learn about entanglement and Bell's inequalities tests, about the case of a pair of photons entangled in polarization, which is the system that has lead to the first convincing experiments. consequences about our understanding of the quantum world will be addressed, leaving to the next lesson the description of some quantum technologies based on entanglement.

ENTANGLEMENT BASED QUANTUM TECHNOLOGIES

The second quantum revolution is not only conceptual, with the understanding of the extraordinary character of entanglemnt, but it also promises to be technological, with applications impossible to conceive before realizing the potential of entanglement. Entanglement based quantum cryptography and the fascinating concept of quantum teleportation are the quantum technologies at the root of quantum networks, the so-called quantum internet, and in this lesson you will understand in detail their principles. In order to build a long distance quantum network, one needs good quantum memories, a very important challenge at the moment. You will also find in this lesson, with less details, the basic idea of quantum simulators, which was introduced by Feynman in 1982, but which came of age only in the recent years. It offers, in 2019, the fascinating perspective not only to elucidate physics phenomena too hard to be solved on a classical computer, such as High Critical Temperature Superconduction, but also to solve hard practical optimization problems, thanks to the concept of NISQ (Noisy Intermediate Scale Quantum) simulators, which do not need to be perfect.

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Examines the second quantum revolution, which has the potential to bring about technological advancements and applications that were previously impossible to conceive

Explores quantum technologies based on entanglement, such as quantum cryptography and teleportation, which are essential for establishing quantum networks

Provides insights into Noisy Intermediate Scale Quantum (NISQ) computing, an emerging area with the potential to demonstrate quantum advantage in the near future

Taught by recognized quantum physics experts Alain Aspect and Michel Brune, providing learners access to unique perspectives from leading researchers

Presents a clear introduction to the basic principles of light quantization and the standard formalism of Quantum Optics, making it accessible to learners with a basic understanding of quantum mechanics

May require learners to have a strong background in quantum mechanics, as it builds on the concepts introduced in Quantum Optics 1, Single photons

Reviews summary

Quantum optics: two photons and more

Learners say this course is well received and contains engaging assignments but difficult exams. This course is well received for its knowledgeable instructors and relevant content featuring quantum optics theories. However, learners note the difficult exams and would appreciate more challenging assignments.

The course offers assignments that help learners engage with the material.

"This course gives me many concepts and tools which are very important for my research."

"This was a fascinating journey. The material is extremally interesting and Prof Aspectdelivers it in the best manner."

"A very insightful course that looks into the fundamentals, evolution and future of Quantum Optics."

The course covers relevant topics in quantum optics.

"The suggested reading material and papers are very helpful!"

"Quantum Optics plays a key role in understanding the matter-light interaction and also various quantum phenomena."

"This course presents many relevant examples of current applications of quantum optics."

The instructors are experts in quantum optics.

"The lectures are very clear and smooth."

"Dr. Aspect is charming and knowledgeable."

"The Professor, the instructor is the best!"

The exams in this course are challenging.

"The course is a series of excellent lectures, covering fascinating topics."

"It would be improved if copies of the lecture slides for lectures 3-5 were provided, along with solutions for Homework 1."

"The homework not being challenging enough."

Activities

Be better prepared before your course. Deepen your understanding during and after it. Supplement your coursework and achieve mastery of the topics covered in Quantum Optics 2 - Two photons and more with these activities:

Review Maxwell's Equations

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Review Maxwell's Equations to refresh your understanding of the fundamental laws of electromagnetism.

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Read through your lecture notes or textbook chapters on Maxwell's Equations.
Solve practice problems related to Maxwell's Equations.
Watch online videos or tutorials on Maxwell's Equations.

Read "Quantum Optics: Theory and Practice" by Marlan O. Scully and M. Suhail Zubairy

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Read a comprehensive textbook on quantum optics to strengthen your theoretical understanding and learn about advanced topics.

View Quantum Optics on Amazon

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Obtain a copy of the book.
Read the book chapter by chapter, taking notes and highlighting important concepts.
Solve the end-of-chapter problems to test your understanding.

Solve Quantum Optics Problems

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Practice solving quantum optics problems to improve your understanding of the concepts and techniques.

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Find practice problems in your textbook or online.
Solve the problems step-by-step, showing your work.
Check your solutions against the provided answers or consult with a tutor if needed.

Four other activities

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Join a Quantum Optics Study Group

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Join a study group to discuss quantum optics concepts, share insights, and reinforce your learning through peer interactions.

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Find or create a study group with other students taking the course.
Meet regularly to discuss the course material, solve problems together, and quiz each other.
Prepare presentations on specific topics to share with the group.

Follow Tutorials on Entanglement and Quantum Technologies

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Follow guided tutorials to gain a deeper understanding of entanglement and quantum technologies.

Browse courses on Entanglement

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Search for online tutorials or video lectures on entanglement and quantum technologies.
Choose a tutorial that matches your skill level and interests.
Follow the tutorial step-by-step, taking notes and asking questions as needed.

Design an Experiment to Demonstrate Quantum Entanglement

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Create a design for an experiment to demonstrate quantum entanglement, showcasing your understanding of the principles and applications.

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Research different methods for demonstrating quantum entanglement.
Design an experiment that meets your desired parameters, such as the type of entanglement and the measurement techniques.
Create a detailed plan for the experiment, including the equipment and procedures.

Build a Quantum Optics Simulation

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Create a simulation to model quantum optics phenomena, deepening your understanding of the principles and applications of quantum optics.

Browse courses on Quantum Optics

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Choose a specific quantum optics phenomenon to simulate.
Research the underlying physics and mathematical models of the phenomenon.
Develop a computational algorithm to simulate the phenomenon.
Implement the algorithm in a programming language.
Test and validate the simulation by comparing the results with theoretical predictions or experimental data.

Career center

Learners who complete Quantum Optics 2 - Two photons and more will develop knowledge and skills that may be useful to these careers:

Quantum Physicist

Quantum Physicists devise theories that describe the behavior of matter at the atomic and subatomic level and conduct research on topics such as quantum mechanics, quantum field theory, and particle physics. Quantum Optics is the study of light and its interactions with matter at the quantum level. This course is a good fit for landing a job in this field. It provides a foundation for understanding the quantum mechanical behavior of light.

See salaries and explore the career path for Quantum Physicist

Quantum Information Scientist

Quantum Information Scientists develop new ways to store, process, and transmit information using quantum mechanics. This course is a good fit for landing a job in this field as it introduces the basics of the field and goes into detail on how quantum entanglement can be used to advanced the field.

See salaries and explore the career path for Quantum Information Scientist

Quantum Researcher

Quantum Researchers conduct research on quantum mechanics and its applications. This course is a good fit for landing a job in this field. It provides a foundation for understanding the quantum mechanical behavior of light at the multimode, quasi-classical level.

See salaries and explore the career path for Quantum Researcher

Quantum Communication Engineer

Quantum Communication Engineers design and build quantum communication systems, which use quantum mechanics to transmit information securely. This course is a good fit for landing a job in this field. It introduces the basics of quantum optics and goes into detail on how quantum entanglement can be used for quantum teleportation and quantum cryptography.

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Quantum Educator

Quantum Educators teach quantum mechanics and related topics at the university level. This course is a good fit for landing a job in this field. It provides a deep understanding of the basic principles of quantum optics.

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Quantum Cryptographer

Quantum Cryptographers develop new ways to encrypt and decrypt information using quantum mechanics. This course is a good fit for landing a job in this field. It provides a foundation for understanding the quantum mechanical behavior of light and provides an introduction to quantum cryptography.

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Quantum Metrologist

Quantum Metrologists develop new ways to measure quantum properties of matter. This course is a good fit for landing a job in this field as it covers the basics of quantum optics and provides a foundation for understanding the quantum mechanical behavior of light.

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Quantum Teleportation Engineer

Quantum Teleportation Engineers design and build quantum teleportation systems, which use quantum mechanics to transport information from one location to another. This course is a good fit for those who want to work in the field of quantum communication. The course covers the basics of quantum optics and goes into detail on how quantum entanglement can be used for quantum teleportation.

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Photonics Engineer

Photonics Engineers design, develop, and test devices that use light to perform various functions, such as transmitting data, generating images, and sensing chemicals. This course is a good fit for those working in the area of quantum cryptography. The course introduces quantum cryptography.

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Quantum Computing Engineer

Quantum Computing Engineers design and build quantum computers, which are new types of computers that use quantum mechanics to perform calculations. This course may be useful for those who are working in the area of NISQ computing. The course introduces the basics of quantum computing.

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Quantum Simulation Engineer

Quantum Simulation Engineers design and build quantum simulators, which use quantum mechanics to simulate the behavior of other quantum systems. This course may be useful for those who work in the area of quantum simulation of materials. The course covers the basics of quantum optics and provides an introduction to quantum simulation.

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Optical Engineer

Optical Engineers design, develop, and test optical systems used in a variety of applications, including telecommunications, imaging, and lasers. This course may be useful for advancement in this role if one wants to work in the area of quantum communication. The course goes in detail about how quantum entanglement is used for quantum teleportation.

See salaries and explore the career path for Optical Engineer

Quantum Software Engineer

Quantum Software Engineers develop software for quantum computers. This course may be useful for those who work in the area of quantum algorithms. The course covers quantum technologies and introduces the concepts needed for quantum algorithms.

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Laser Scientist

Laser Scientists design, develop, and test lasers, which are devices that emit highly concentrated beams of light. This course may be useful for those who work in the area of laser beam characterization. The course covers how to describe classical light, including coherent light such as laser light.

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Quantum Sensing Engineer

Quantum Sensing Engineers design and build quantum sensors, which use quantum mechanics to detect and measure physical properties of matter. This course may be useful for those who work in the area of quantum magnetometry. The course covers how squeezed light can be used to beat the Standard Quantum Limit.

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