JUPITER supercomputer fully simulates a 50-qubit quantum computer

Researchers at Germany’s Jülich Supercomputing Centre, working with NVIDIA, say they have fully simulated a universal 50-qubit quantum computer on JUPITER, Europe’s first exascale supercomputer. The result, announced Nov. 11, 2025, exceeds a 48-qubit record set by Jülich researchers in 2019 on Japan’s K computer.

The advance is a simulation, not a 50-qubit quantum processor. Classical simulations let researchers verify experimental results and test quantum algorithms before quantum hardware can run them at scale. Jülich points to the Variational Quantum Eigensolver, used to model molecules and materials, and the Quantum Approximate Optimization Algorithm, aimed at optimization problems, as potential applications.

The computing burden grows exponentially with each added qubit. Jülich says simulating 50 qubits requires about 2 petabytes of memory, and that each operation affects more than 2 quadrillion complex numerical values that must be coordinated across thousands of computing nodes.

The team attributed the result to JUPITER’s NVIDIA GH200 Superchips, which pair CPUs and GPUs and allow data exceeding GPU memory capacity to be held in CPU memory. Researchers also modified Jülich’s JUQCS simulation software to work with that arrangement, used a byte-encoding compression method that cuts memory needs eightfold, and developed a dynamic approach to managing data transfers across more than 16,000 GH200 Superchips.

The researchers say the updated simulator, JUQCS-50, can emulate universal quantum computers with high fidelity. The work was carried out through JUPITER’s Research and Early Access Programme, in which Jülich and NVIDIA worked on hardware and software together while the system was under construction. Jülich identifies the team’s study as a preprint.

Jülich says external research institutions and companies will be able to access JUQCS-50 through JUNIQ, its quantum-computing infrastructure. The center presents the simulator as both a research tool and a benchmark for future supercomputers; the announcement does not describe it as a substitute for quantum hardware.