Quantum Simulation Explained: Applications, Methods and Challenges

Insider Brief

• Quantum simulation uses quantum computers to model molecules, materials and other quantum systems that can be difficult to simulate efficiently on classical computers.
• Digital and analog quantum simulation take different approaches, with digital systems offering broader flexibility and analog systems targeting specific physical problems.
• Current quantum simulation remains largely at the research stage, with practical applications dependent on larger systems, lower error rates and demonstrated advantages over classical methods.

A molecule with fifty interacting particles needs more numbers to describe its full quantum state than a classical supercomputer can store. That’s the wall classical chemistry keeps hitting, and it’s why physicist Richard Feynman proposed the idea that if you want to simulate a quantum system accurately, build a computer that runs on quantum mechanics too.

Quantum simulation applies this idea to systems that are difficult to model on classical computers. Molecules, materials, and quantum computers all follow the same laws of quantum mechanics, so researchers can use a quantum computer to represent the behavior of a molecule and simulate how that system evolves. This can provide a more direct way to study quantum systems than calculating their behavior entirely on a classical machine.