28/02/2020 12:19

Between theory and application, the promise of quantum computers

  • Physics

Mario Leandro Aolita

Clarice Cudischevitch

Quantum computers are one of the greatest promises of the so-called Information Age. Research groups around the world are focused on building this technology—in 2019 Google announced that it had manufactured a quantum computer that would execute in minutes what would take the fastest supercomputer today 10 years to process. Mario Leandro Aolita of the Institute of Physics at the Federal University of Rio de Janeiro (UFRJ), aims to make strides on along this path by making a connection between basic and applied research.

A Serrapilheira grantee, Aolita just had his support renewed and will receive R$700,000 from the Institute, plus an optional bonus of R$300,000 for integrating and training people from underrepresented groups in science. Despite the grandness associated with the promise of quantum computers, it is in the microscopic world—that of atoms and photons—that the theoretical physicist works to study quantum systems. These systems are different from those governed by the laws of classical Newtonian (pre-quantum) physics, which govern the microscopic world that we perceive in our daily lives.

Aolita’s research belongs to a field of physics that emerged in the late 1980s, quantum information. This field stemmed from the interaction between quantum mechanics (the theory at the heart of modern physics) and information theory (originally based in mathematics and computer science). Quantum information harnesses the counterintuitive properties of quantum mechanics like quantum superposition and quantum entanglement for storing, processing and sending information more efficiently than classical systems.

Aolita’s project is divided into several parts. Regarding that which is more focused on applications, Aolita seeks to develop quantum computers, which promise to be able to solve problems that no conventional computer (not even the supercomputers of today) are capable of solving. In order to do so, Aolita creates quantum algorithms equipped to more efficiently solve problems with applications in the fields of artificial intelligence or machine learning.

His research group also uses classical machine learning to try to characterize the prototypes of quantum devices being built. “Verifying and characterizing experimental quantum computers is a highly non-trivial task because the devices we want to build are explicitly meant to have vastly superior processing power than that of today’s conventional computers.”

In other words: the challenge lies in validating the performance of an extremely powerful computational system with devices whose capacity is vastly inferior.

Another area Aolita is working on is quantum cryptography. He develops models for communication, encryption and randomization that are directly protected by the laws of quantum physics, thus rendering them much more secure than classical cryptography. This is because in classical cryptography security is based on the difficulty of hacking a code (i.e., the computational difficulty of solving a coded mathematical problem).

“Quantum cryptography is secure even if the hacker in question has all the computational power in the world because the security in this type of cryptography is based on the laws of physics.” Rafael Chaves, another physicist at Serrapilheira whose grant was renewed, also works in this field. Learn more.

Now, taking a more basic approach, Aolita studies the connection between entanglement and quantum superposition and causality in connection with Einstein’s theory of relativity and other possible theories (yet to be developed) of quantum gravity.

Being able to work in such a broad scope of theoretical physics is due to a multidisciplinary and diverse education. Born in the small Argentinian city of Zárate, 85 km from Buenos Aires, Aolita graduated from the University of Buenos Aires with undergraduate and master´s degrees in physics. He pursued his PhD at the Federal University of Rio de Janeiro (UFRJ), where he studied under his advisor, Luiz Davidovich, one of the most prominent names in quantum physics in Latin America. Aolita continued his studies through post-doctoral fellowships at the Institute of Photonic Sciences (ICFO) in Barcelona, Spain, and at the Free University of Berlin (FUB), Germany.

“I feel very privileged to have received the education I did,” states Aolita, who says he is a nature lover and has practiced yoga and meditation for over ten years. “I was able to cover aspects both applied and basic, theoretical and experimental, and many different topics. This has enabled me to have a broad perspective of the field and where it is going.”

Ever since the beginning of his undergraduate career, Aolita was interested in quantum mechanics, but his fondness for science goes further back, to his childhood, when he read scientific magazines. In secondary school, a physics teacher inspired him to explain the first pre-quantum atomic models (such as those of Rutherford and Bohr). “I realized I wanted to learn more about that. I think that the main difference was that regardless of the topic I explained, the teacher taught us how to think logically instead of memorizing formulae. This had a major impact on me, since it taught me to solve unknown problems using my own power of logic.”

  • Topics
  • mario leandro aolita
  • quantum computer
  • quantum physics