Research > Quantum Information & Computation

Quantum Information & Computation


The laws of quantum mechanics govern the behavior of infinitesimal particles such as individual photons or electrons. As computers and their microprocessors become smaller and smaller it becomes increasingly necessary to take into account quantum phenomena in order to accurately predict their behavior. Rather than a hindrance, the field of quantum computing sees this as an opportunity to develop a radically novel model of computation which uses quantum phenomena in order to develop:

  • Algorithms that run faster than any algorithm known for classical computers,
  • Cryptosystems that are more secure than any classical cryptosystem could ever be,
  • Coding procedures that go beyond information-theoretic limitations on classical codes, and much more!

The quantum computing group at CMS benefits from a close collaboration with Caltech’s Institute for Quantum Information and Matter, partly co-located within the same building. As a result our research takes a strong interdisciplinary bent. Our approach consists in identifying challenges in quantum information and the study of quantum systems for which the use of computer science techniques, from algorithms, complexity, cryptography or information theory, can lead to major advances.

A sample recent focus of interest of our group has been the study of the computational consequences of “quantum weirdness”: we approach the nonlocal properties of entanglement from the complexity-theoretic (multiprover interactive proofs) and cryptographic (device-independent quantum key distribution) vantages. Inspired by our collaborators from physics we develop classical and quantum algorithms for the simulation of quantum mechanical systems, contributing to the understanding of new phases of matter. We are also excited by the prospects of topological architectures for quantum memories and quantum error-correcting codes. Our point of view is that quantum computing is not the future: it is the present! Quantum mechanical systems are everywhere, with a strangeness and power that is only awaiting a computational mindset to be properly understood and harnessed.

For more information on Quantum Science & Engineering at Caltech, see


Fernando Brandão, Alexei Kitaev, John Preskill, Gil Refael, Leonard Schulman, Thomas Vidick

Related research groups & Centers > IQIM, Theory group, CMI

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