Lockheed Martin and IBM combine quantum computing with HPC in new research

Summary

In a new paper published in The Journal of Chemical Theory and Computation, researchers from IBM Quantum® and Lockheed Martin demonstrate how a quantum computer can help accurately model the electronic structure of certain molecules. These so-called, “open-shell” molecules contain one or more unpaired electrons, making them difficult to simulate with classical methods alone. The new research marks the first application of the sample-based quantum diagonalization (SQD) technique to open-shell systems — an important milestone for quantum chemistry and its applications in aerospace, sensing, and materials design. IBM® researchers believe that SQD is a prime candidate for near-term demonstrations of quantum advantage, as it allows researchers to combine the best of high-performance quantum computers and high-performance classical computers in tackling interesting simulation problems. Quantum computing for chemistry: Why now? Quantum chemistry has long stood out as one of the most promising applications for quantum computing. Many chemical systems — particularly those involving strong electron correlation, e.g., transition metals, radical species, transition states, or excited states — are exceptionally hard to simulate using classical high-performance computing. The computational cost of exactly modeling these systems with classical computers grows exponentially with the number of interacting electrons, making exact solutions practically inaccessible for even relatively small molecules. While there are some classical approximation methods that can simulate chemical systems with strong electronic correlation, these methods are computationally expensive. This is where quantum computers could come in. Quantum chemistry simulations run on quantum computers can accurately compute the electronic structure and energies of these systems as an alternative to classical methods. As quantum computers progress toward fault-tolerance, it is possible that they will be able to simulate...