Exploring the vast potential of quantum computing, one of the most exciting areas of research is simulating proteins to facilitate new drug discovery. Currently, quantum devices are hampered by errors, making them less suitable for this purpose. However, a groundbreaking collaboration involving supercomputers and two quantum systems has set a new record by accurately simulating a molecule containing 12,635 atoms.

Determining the quantum state and energy levels of drug molecules is essential for understanding how they behave, a task often only achievable through approximate methods on traditional computers. A team of researchers from Cleveland Clinic, IBM, and Japan’s Institute of Science and Technology focused on developing quantum computers that inherently utilize quantum physics principles. They innovated a hybrid model combining quantum and classical supercomputing for unprecedented simulations of large molecular structures.

“This was my dream, and here we are,” says Kenneth Mertz from Cleveland Clinic. In this study, the researchers utilized two IBM Heron quantum computers located at RIKEN and Cleveland Clinic, alongside the world’s most powerful supercomputers, Fugaku and Miyabi-G. Their approach focused on simulating a protein-ligand complex, a well-studied example pivotal for biomedical research, while also examining the molecules in a water layer that reflects laboratory conditions.

Currently, the limited size and inherent error rates of quantum computers restrict their utility. Thus, the research team divided the molecular simulation tasks among four machines. The quantum computer was tasked with calculating specific properties, and the results were transferred back and forth with the supercomputer over 100 hours. Despite the lengthy process, the team believes it was faster than traditional methodologies. Jerry Chow at IBM noted that the simulation accurately estimated the lowest energy state of the molecule, matching the precision of conventional methods, though it hasn’t yet proven markedly superior.

According to Liu Junyu from the University of Pittsburgh, this research signifies a crucial milestone towards achieving practical applications of quantum computing with real-world hardware. He expressed admiration for the scale of the experiment. Even prior to achieving error-free quantum computing, there is a necessity to explore hybrid methods further to enhance the usefulness of quantum systems.

Chow added that while their findings indicate that quantum hardware might excel in certain calculations, this simulation record is a preliminary achievement. “There is a growing push to explore the limits of what can be achieved,” Chow acknowledged. “It’s just the beginning of an exciting journey.”