Beginning of A New Chapter in Quantum Information Theory


Dr. Sadegh Raeisi, Assistant Professor at the Faculty of Physics of Sharif University of Technology, in collaboration with an International Research Group from University of Waterloo, Macquarie University, Perimeter Institute for Theoretical Physics, and Canadian Institute for Advanced Research, has published an article titled “Novel Technique for Robust Optimal Algorithmic Cooling” in Physical Review Letters.

Heat-bath algorithmic cooling provides algorithmic ways to improve the purity of quantum states. These techniques are complex iterative processes that change from each iteration to the next and this poses a significant challenge to implementing these algorithms. In this research work, a new technique is introduced that on a fundamental level, shows that it is possible to do algorithmic cooling and even reach the cooling limit without any knowledge of the state and using only a single fixed operation, and on a practical level, presents a more feasible and robust alternative for implementing heat-bath algorithmic cooling. It is also shown that the new technique converges to the asymptotic state of heat-bath algorithmic cooling and that the cooling algorithm can be efficiently implemented; however, the saturation could require exponentially many iterations and remains impractical. This brings heat-bath algorithmic cooling to the realm of feasibility and makes it a viable option for realistic application in quantum technologies.

The study could be the beginning of a new chapter in quantum information theory, which transforms use of algorithmic cooling into realistic alternatives for practical applications in quantum technologies. It’s worth noting that the Physical Review Letters is the most authoritative journal of the American Physical Society which publishes the latest and most influential physics research.

Dr. Raeisi’s research is mostly focused on foundations and practical aspects of theory of Quantum Mechanics; Macroscopic Quantumness, Algorithmic Cooling, Optomechanics. To find out more you might visit his personal page at:




© 2019 American Physical Society