Nvidia simulates 104-qubit fault-tolerant quantum computer on JUPITER

Nvidia has simulated a 104-qubit quantum computer that can correct its own errors, using JUPITER, the supercomputer at Germany’s Jülich Supercomputing Centre. The company said it is the largest full simulation of such a machine so far.

Qubits are the building blocks of quantum computers, but they’re extremely sensitive to interference. Even small amounts of noise from the control equipment can cause errors.

A fault-tolerant quantum computer can detect and correct those errors while running. Most experts consider this a key step towards making quantum computers practically useful.

The team tested a technique called magic state cultivation, which helps quantum computers carry out certain calculations. These special quantum states are needed for many operations, but creating them can require many extra qubits. Nvidia says its method uses 90% fewer qubits than earlier approaches.

The simulation also accounted for the noise that affects real quantum hardware. That builds on work by researchers at Jülich, who simulated 50 qubits on JUPITER in November 2025 under ideal, noise-free conditions.

JUPITER, which opened in September 2025, was Europe’s first exascale supercomputer. It can perform more than a billion billion calculations per second. For this latest test, the team used Nvidia GH200 chips across 8,192 GPUs.

Nvidia first developed and tested the model on a smaller system at its own quantum lab, cutting the work from weeks to days, the company said.

The idea is to help researchers test how a quantum computer design might perform before building the actual hardware. The entire simulation ran on conventional computers, not a quantum processor.

“Useful quantum computing will require fantastically complex, fault-tolerant systems,” said Nvidia CEO Jensen Huang.

“Europe’s investment in JUPITER gives researchers the ability to investigate questions that were previously beyond reach,” said Kristel Michielsen, director of the Jülich Supercomputing Centre.

The announcement comes as Huang prepares to deliver his keynote at Nvidia’s GTC conference in Berlin on Wednesday. Earlier this week, Germany signed an AI partnership with Nvidia at an investment summit in the capital.