TouQan

Towards a useful quantum advantage

Quantum simulation has emerged as a particularly promising venture within the growing field of quantum technologies. Quantum simulators are experimental devices which typically take the form of arrays of atoms or other quantum particles, with the important feature that their configuration and the interactions between them can in principle be tuned with a high degree of controllability.
This means that they have the potential to reproduce highly complex quantum systems in completely new ways, allowing us to probe previously uncharted realms of physics.
One can think of the quantitative information we get from these experiments in terms of
computations: the quantities we can measure in those systems can be understood as the solutions to computational problems, in the same way as we routinely simulate physical systems in standard computers. However, with these novel machines, what is the ultimate complexity of the problems that they can solve?
There concrete physical evidence that quantum simulators have already achieved a so-called quantum advantage, in which computations of physical quantities seemingly beyond the scope of our usual computers have already been possible. However, we still have an incomplete theoretical understanding of whether that “quantum advantage” has already been reached in a rigorous sense, and if so, when and how has it happened. Studies of such an advantage have received considerably less attention and scrutiny than similar recent claims made for digital quantum computers, such those based on random circuit sampling.
TouQan aims to bridge the gaps in our theoretical understanding of potential quantum advantages in quantum simulators. In order to do this, we will advance our knowledge of the range of physical problems that can be reliably simulated by both classical and quantum means, with an emphasis on rigorous estimates of simulation costs, as well as on the impact of hardware noise. By doing so, we will build towards a clearer picture of the computational power of near-term and future quantum simulators.

CONSORTIUM