Quantum computing leverages quantum mechanical phenomena in order to solve certain problems faster than ordinary classical computers possibly can, like simulating nature and solving certain optimization problems. However, quantum gates are much more error-prone than classical gates and hence quantum computation needs to be protected by powerful quantum error-correcting codes. While most theoretical results in quantum information and computation are developed assuming that quantum resources are unlimited, we are interested in what can be achieved with limited quantum resources using realistic circuit-level noise models. Moreover, we study the distributed setting in which several quantum processing units collaborate in order to solve a complex task, which naturally requires efficient creation and distribution of entanglement as well as tailor-made quantum error-correcting codes.
Practically, this research addresses the critical bottleneck of scaling up quantum computational power. Because building a single, massive fault-tolerant quantum computer is incredibly difficult, connecting multiple smaller quantum processors into a distributed quantum network allows us to bypass the physical constraints of individual devices. This distributed approach, combined with our work on handling circuit-level noise, is the necessary stepping stone to unlocking real-world quantum advantage. Ultimately, these architectures will accelerate complex tasks that classical supercomputers cannot handle.
