Universal quantum computer simulation of 50 qubits on Europe’s first exascale supercomputer harnessing its heterogeneous CPU–GPU architecture
Hans A. De Raedt, Jiri Kraus, Andreas Herten, Vrinda Mehta, Mathis Bode, Markus Hrywniak, Kristel F. L. Michielsen, Thomas Lippert · Future Generation Computer Systems · 2026
We have developed a new version of the high-performance Jülich universal quantum computer simulator (JUQCS-50) that leverages key features of the GH200 superchips as used in the JUPITER supercomputer, enabling simulations of a 50-qubit universal quantum computer for the first time. JUQCS-50 achieves this through three key innovations: (1) extending usable memory beyond GPU limits via high-bandwidth CPU–GPU interconnects and LPDDR5 memory; (2) adaptive data encoding to reduce memory footprint with acceptable trade-offs in precision and compute effort; and (3) an on-the-fly network traffic optimizer. These advances result in an 16.6-fold speedup over the previous 48-qubit record on the K computer.