Transporting quantum information between various (parts of) quantum computers is an essential ingredient for quantum technologies, and is stated as one of DiVincenzo’s criteria. Still, high-fidelity transport over significant distances remains challenging for most platforms that are not based on photons.

Koen will consider a network of sites (you may think of them as qubits) laid out in real space, whose allowed interactions are given by a graph.

It turns out that, under certain graph restrictions, quantum information can be transferred between certain sites. This requires only local control over the interactions connecting the sender/receiver, thus allowing passive “cables” to be laid between the communicating parties.

This generalizes previous work, which was mostly limited to linear chains, to a much broader set of graphs, and to transport between more than two parties. The protocol turns out to inherit all robustness features that helped the conventional linear protocol (so-called STIRAP) to become a widely adopted experimental technique.

The talk is based on a work in progress together with Carla Groenland and Reinier Kramer, and to a lesser extend on

https://scipost.org/SciPostPhys.6.1.011.

In the pre-seminar, at 10.30 AM, Koen will give an introduction about quantum dynamics (the evolution of states in time), targeting an audience of computer scientists and mathematicians who have little experience working with Hamiltonians or Schroedinger’s equation.