Simulation

​Assessing performance

The advantages: all simulated qubits work one hundred percent reliably – in contrast to real qubits, where errors often occur. Comparing simulation and reality allows the computational quality of a quantum computer to be assessed. In addition, algorithms that will be run on quantum computers in the future can be developed and tested.

However, simulations are also used to investigate the properties of potential quantum materials – for example, the performance of Majorana qubits, a possible future qubit type that is less prone to errors than semiconductor and superconducting qubits.

​World record for simulated qubits

Jülich’s emulator for quantum computers is known as the Jülich Universal Quantum Computer Simulator (JUQCS). With 48 qubits, it holds the world record for the highest number of simulated qubits. To achieve this, Jülich scientists used the Sunway TaihuLight (China) and K (Japan) supercomputers.

However, simulating more than 48 entangled qubits is considered difficult, as every additional qubit doubles the memory requirement of the computer on which the simulation is running. Even state-of-the-art supercomputers reach their limits at this point.

Simulations on Jülich’s supercomputer JUWELS also contributed to Google’s demonstration of quantum supremacy in 2019. The term describes the point from which a quantum computer outperforms conventional computers in a particular task for the first time. Proving this had been considered a major challenge. The simulations on JUWELS helped verify the results and determine the performance of Google’s quantum processor.

​Simulation of quantum materials

The Simulation and Data Laboratory Quantum Materials at the Jülich Supercomputing Centre offers scientists the opportunity to carry out simulations in the field of quantum materials as well as calculations of the quantum mechanical properties of materials. For this purpose, the laboratory develops and optimizes mathematical models and tools.

Jülich Supercomputing Centre (JSC)

Further Information

Feature story

How prime numbers help improve the quantum computer

Scientists at the Jülich Supercomputing Centre have set a new world record: they simulated a quantum computer with 48 qubits on two different supercomputers. In order to test the limits of their simulated quantum computer, they used a method that requires the highest computing capacities: the prime factorization of large numbers. In their simulated quantum computer, the scientists implemented the so-called Shor’s algorithm so successfully that they could use it for a number of previously unattained size.

Press release

Forschungszentrum Jülich Contributed to Google’s Demonstration of Quantum Supremacy

After rumors had been spreading for weeks, now it’s official. Google and collaborators, including Forschungszentrum Jülich, have achieved a milestone in quantum computing called quantum supremacy as the researchers claim in the renowned journal “Nature”. The term marks the moment when a quantum computer, for the first time, outperforms state-of-the-art conventional computers for a specific task.