Open Quantum Systems and Quantum Algorithms

The somewhat bizarre phenomenon of quantum entanglement allows for a new type of information storage that is uniquely quantum mechanical in nature. This ‘quantum information’ intrinsically stores quantum mechanical information in a natural and compact way that would otherwise require exponentially large resources on a classical computer. In order to utilize and process this information, special algorithms that operate on quantum mechanical systems can be developed that allow exponentially difficult classical computations to become tractable by letting nature do all the hard work of keeping track of various quantum mechanical parameters in the calculation. In this way quantum systems can be used to obtain or store information about other quantum systems.

Our group focuses on the development and extension of efficient quantum algorithms for quantum simulation of chemical systems, reaction dynamics, state preparation, and the development of methods by which these algorithms can be successfully carried out quantum computers. We also study open quantum system dynamics and the impact of environmental factors that affect the execution of quantum algorithms. We focus on methods for maintaining high degrees of coherence in our algorithms in the presence of environmental decoherence within quantum computers, and efficient methods for measurement of desirable properties of simulated chemical systems.

Representative Publications
  1. César Rodríguez-Rosario, Gen Kimura, Hideki Imai, and Alán Aspuru-Guzik. Sufficient and Necessary Condition for Zero Quantum Entropy Rates Under Any Coupling to the Environment. Physical Review Letters 106, no. 5 (February 2011).
  2. Zhaokai Li, Man-Hong Yung, Hongwei Chen, Dawei Lu, James D. Whitfield, Xinhua Peng, Alán Aspuru-Guzik, and Jiangfeng Du. Solving Quantum Ground-State Problems with Nuclear Magnetic Resonance. Scientific Reports 1 (September 9, 2011).
  3. Man-Hong Yung, Daniel Nagaj, James Whitfield, and Alán Aspuru-Guzik. Simulation of Classical Thermal States on a Quantum Computer: A Transfer-matrix Approach. Physical Review A 82, no. 6 (December 2010).