# Román Orús

Román Orús Lacort (Barcelona, 1979) is a Spanish theoretical physicist who specializes in quantum information science and quantum tensor networks. He is Ikerbasque Research Professor at the Donostia International Physics Center (DIPC), as well as co-founder and Chief Scientific Officer of Multiverse Computing.

## Education and career

Román Orús studied physics at the University of Barcelona where he obtained his Ph.D. supervised by José Ignacio Latorre in 2006. Orús' doctoral thesis, “Entanglement, quantum phase transitions and quantum algorithms," connected quantum algorithms with quantum phase transitions.
Afterwards he developed tensor networks to study high-dimensional quantum complex systems as a research fellow at the University of Queensland (Brisbane, Australia) with Guifré Vidal, and at the Max Planck Institute of Quantum Optics (Garching, Germany) with Ignacio Cirac.
He became Junior Professor of Condensed Matter Physics at the Johannes Gutenberg-Universität (Mainz, Germany) in 2013, and Ikerbasque Research Professor at DIPC (San Sebastián, Spain) in 2018. He also held visiting professorships at CNRS (Toulouse, France) and DIPC and has lectured at the Institute for Pure and Applied Mathematics at UCLA.
In 2014 he published “A Practical Introduction to Tensor Networks” which describes the applications of Matrix Product States and Projected Entangled Pair States for optimization, quantum gravity, and the study of quantum many-body systems.
Orús' research on tensor networks for complex quantum systems contributed to the field's modern research and applications in machine learning.
In 2018, Orús wrote an article with Sam Mugel and Enrique Lizaso on the practical applications of quantum computing in finance. This demonstration of quantum and financial technology for enterprise led to the creation of Multiverse Computing in 2019.
Orus’ work on quantum and quantum-inspired solutions at Multiverse has also been used in projections on the future intersection of artificial intelligence and quantum computing.

## Scientific work

In 2023, Orus developed an algorithm for executing complex calculations on noisy intermediate scale quantum computers to solve specialized problems like optimization.
Also in 2023, Orus designed a quantum-enhanced kernel method for image classification, applying quantum artificial intelligence to identify manufacturing defects.
In cybersecurity, Orús demonstrated examples of possible quantum cyberattacks for symmetric-key cryptographic protocols such as AES and Blowfish that could make those ciphers vulnerable using few-qubit quantum processors.
He also developed industrial applications of tensor networks for machine learning, using tensor networks to compress Large Language Models such as ChatGPT and LLaMA, reducing size while retaining most of the original accuracy to improve energy costs and efficiency.
In 2014, Orús designed a tensor network algorithm to characterize topologically ordered systems with quantum many-body entanglement.

## Recognition

Orús received the 2024 Physics, Innovation and Technology award from the Spanish Royal Society of Physics, which recognized Orús’ career, patents, and contributions in the field of quantum technologies.
Other awards include an honorable mention in the Václav Votruba Prize (2008), a Marie Curie Incoming International Fellowship (2009) and the Early Career Prize of the European Physical Society (2014), which he won alongside Ian Chapman.
Orús is steering board member of the journal Quantum as well as a member of the editorial board of the journal Symmetry.