A quantum simulator is a quantum system that helps to solve a specific problem that is difficult to solve otherwise. Hence, its classical simulation and also its tomographic characterization are difficult. But if one cannot know the outcome, how can one then be sure that it works as one hopes it works? Solving this problem is the goal of certification.

The goal of quantum simulations is to solve a problem that cannot practically be solved on classical computer. But how can one then be convinced that it functions as desired?

This challenging task is called certification.

Quantum states

Bosonic linear optics states

Fermionic linear optics and integrable spin chains

Ground states

Quantum dynamics

Quantum states can be certified, even if they cannot be classically simulated efficiently, see here. Does the same hold for quantum dynamics? Quantum process tomography is expected to be crucial for this task.