Tura, Jordi and Schiffer, Benjamin

Date: Thursday, January 25, 2024
Time: 11:00
Place: ETH Campus Hönggerberg, HIT E 41.1
Host: Johannes Knörzer

Quantum protocols for state preparation in distributed quantum computing

Jordi Tura - Leiden University, The Netherlands
Benjamin Schiffer - Max Planck Institute of Quantum Optics, Germany

Abstract: The concept of distributed computing has provided significant advances in computer science. However, in the quantum domain it remains largely unexplored, especially in the setting where quantum computers are connected with coherent links. The ability to achieve such coherent quantum communication with good fidelities has only recently become a reality, laying the groundwork for practical applications in distributed quantum computing. This talk presents an overview of essential algorithms in this area, along with two specific contributions from our research. The first is a method for accurately measuring the ground state overlap in adiabatic quantum algorithms without prior knowledge of the ground state. This technique has practical implications for quantum simulation and optimization. Our second contribution explores a method for preparing an eigenstate by connecting to a second quantum device that already holds the state. By exploiting a quantum link, we demonstrate how the ground state can be effectively "broadcasted" in a specific scenario that circumvents the constraints imposed by the no-cloning (and no-broadcasting) theorem.

[1] Schiffer, B. F., Tura, J., & Cirac, J. I. (2022). Adiabatic spectroscopy and a variational quantum adiabatic algorithm. PRX Quantum, 3(2), 020347.
[2] Schiffer, B. F., & Tura, J. (2023). Quantum eigenstate broadcasting assisted by a coherent link. arXiv preprint arXiv:2302.03017.