## It's a Quantum World!

Quantum physics is the most counter-intuitive theory ever produced. It challenges our most basics intuitions, yet its provides astonishingly accurate predictions on the behavior of matter and energy on the scale of atoms and below. More surprisingly, the paradoxes of quantum physics are being turned into promising technologies. We are soon going to witness the second revolution of quantum technologies, and although Arthur C. Clarke said that “any advanced enough technology is indistinguishable from magic”, we are sure you would like to know the details of every trick to be able to take the lead!

Before being introduced to the theory of quantum physics, you will be exposed to vector and matrix formalism, to be able to understand the postulates, and to the basics of information theory, to be able to introduce quantum mechanics from the point of view of information. We will finish the theory lessons with a discussion of Bell inequalities.

Then you will be able to explore the effects of measurement on quantum systems through several stages and manipulations on an interferometer. You will manipulate the optical elements of a basic interferometer to understand in a direct and practical way some of the fundamental concepts of quantum mechanics and how they are connected to new technologies.

By manipulating several optical systems you can understand how superposition works and how information plays an important role for quantum physics, leading to surprising effects. You can see how to measure –and then gain information– a system can change it. You can also erase this information –even if the measurement is already done– to restore the system to its initial conditions.

You will also use an optical setup to send information in a secure way, based on the quantum cryptographic protocols, so that you will get in a practical way how quantum physics can improve the security of communications. Quantum physics can help us also to speed up some kinds of calculations: you’ll learn how this is possible and how to interact with a quantum computer.

Richard Feynman, a physicist who was born exactly 100 years ago and contributed greatly to quantum physics, said that it is safe to say that nobody understands quantum mechanics. During your stay here at ICFO we challenge you to prove him wrong, to understand the basics of quantum physics and how many new technologies can stem from it, so that you can be an active part of the second quantum revolution!

Physics, photonics, engineering, mathematics

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## Federica Beduini (ICFO)

Federica Beduini is a Italian physicist, who arrived to Barcelona in 2009 for a PhD in Quantum Optics at ICFO. She is now Outreach Project Manager at ICFO coordinating the educational activities that ICFO organises to spread the passion for light and photonics among young students. For the last Science Week, she organised the first Young Photonic Congress, where more than 80 students from Catalonia had the opportunity to explain their own research projects to their peers and to ICFO researchers.

## John Calsamiglia (GIQ - UAB)

John Calsamiglia graduated in Physics from the UAB in 1996. After postgraduate studies in theoretical physics in U. Autónoma de Madrid, in 1997 he joined the Helsinki Institute of Physics to carry out his PhD on the quantum processing capabilities of linear optics. He held postdoc positions in Harvard-Smithsonian CFA & UCONN (on quantum dynamics of Rydberg ensembles), LMU München (on multipartite quantum communication applications and entanglement) and U. of Innsbruck (on quantum spin-gases, and non-classicality measures), where he was assistant professor until 2005. He returned to UAB with a Ramón y Cajal fellowship, where he is a professor with tenure since 2010. His current research interests are centered on quantum statistical inference and non-classicality. He is author of 53 papers, has supervised 4 PhD thesis and has participated in numerous research projects funded by national and European agencies.

## Ivan Supic (ICFO)

Ivan is a PhD student in Quantum Information Theory group in ICFO. Originally, he is from Montenegro. He got his Physics degree from University of Belgrade and obtained his master’s degree from Polytechnic University of Catalunya. His research interests involve foundations of quantum theory, Bell nonlocality and quantum computing. In his native country he organized several science camps for high-school students.Ivan is a PhD student in Quantum Information Theory group in ICFO. Originally, he is from Montenegro. He got his Physics degree from University of Belgrade and obtained his master’s degree from Polytechnic University of Catalunya. His research interests involve foundations of quantum theory, Bell nonlocality and quantum computing. In his native country he organized several science camps for high-school students.

## Boris Bourdoncle (ICFO)

Boris got his master’s degree in Paris (Télécom ParisTech), then moved to Barcelona in 2014. He is currently a PhD student in quantum information theory at ICFO. He supervised two students from the Youth and Science Program from La Fundació Catalunya La Pedrera and co-organized the 2nd edition of the international conference for Young Quantum Information Scientists (YQIS) in Barcelona in October 2016.

## Zahra Raissi (ICFO)

Zahra is a physicist. Her professional path started a long time ago, when she started to learn about the physics of elementary particles (high energy physics). After that, she got involved to work on a project about black holes, holographic screens and gravity. Currently, she am a PhD student in quantum information theory group at ICFO.

## Xavier Valcarce (ICFO)

Xavier is physics master student at the Claude Bernard University, Lyon. He is currently working on his master thesis in Quantum Information Theory at ICFO in Dr. Antonio Acín’s group. He discovered this field last year while doing an internship in Nicolas Brunner’s group at the University of Geneva. His main interests are on non-locality, many body systems and machine learning.

## Andreu Riera (GIQ - UAB)

Andreu Riera Campeny is and PhD student at the Quantum Information Group (GIQ) from the UAB. He studied his Physics Degree in the same university, and then he moved to Innsbruck (Austria) to study there the MSc. in Theoretical Quantum Physics. He is currently a teaching assistant of the Physics degree at UAB.

## Marta Gil (GIQ - UAB)

Marta Gil studies Physics and Mathematics at the UAB and is currently carrying out the bachelor’s Thesis in the Quantum Information Group at UAB. She has participated in the Youth and Science Program from La Fundació Catalunya La Pedrera, staying in research centers such as the Perimeter Institute in Canada and the Genomic Regulation Center in Barcelona.

## Martí Berenguer (GIQ - UAB)

Martí Berenguer studies Physics at the UAB. He is currently carrying out the bachelor’s Thesis in the High Energy Physics Institute (IFAE) at UAB, and next course he will be taking the Master in Astrophysics, Particle Physics and Cosmology at Universitat de Barcelona.

The It's a Quantum World! project is led by two centers: