What it is
Some materials and molecules are too complex for any ordinary computer to calculate exactly, because the number of interacting quantum particles is too large.
A quantum simulator is a well-controlled quantum system, such as a lattice of cold atoms, that is tuned to behave like the system we want to study.
In the portal's four pillars, simulation is part of the pillar quantum computing and simulation: analogue simulators and simulations run on quantum computers are counted there.
How it works
Atoms are cooled to almost absolute zero and held in a grid of light, an optical lattice. Lasers set how strongly neighbouring atoms interact, and researchers watch how their spins arrange themselves.
Analogue simulators imitate a specific model directly. Digital simulators run it as a quantum circuit on a programmable quantum computer.
Try it: set the spins of a lattice
Each atom has a spin that points up or down. Press atoms to flip them and see how many neighbours agree.
Why it matters
Simulation can help to design better batteries, catalysts, superconductors and drugs, and to test fundamental theories of matter.
It is regarded as one of the nearest useful applications of quantum technology.
Europe’s position
European laboratories are among the leaders in cold-atom and trapped-ion simulators, and Horizon Europe and the Quantum Flagship support both analogue and digital approaches.
598 EU-funded projects in quantum computing and simulation, with an EU contribution of EUR 1,188 million (CORDIS; the pillar is suggested automatically and pending review). Quantum simulation is counted in this pillar since taxonomy 2.0.
On this site
Recent EU-funded projects in quantum computing and simulation
- AQME: Advanced Quantum-Classical Dynamics for Molecular Electronics
- Simulating HIGHER-Order Quantum Computing: From Causal Structures to Quantum Circuit Implementations
- DigiAnaQsim: Digital methods in analog quantum simulation
- MEQSIKO: New methods for 2D-materials quantum simulators: Application to the Kondo model
- QUASIF: Quantum Simulation of Spin-Imbalanced Fermi Gases with Single-Atom Imaging and Control
Glossary
- Optical lattice
- A grid of light that holds atoms in place.
- Spin
- A quantum property of a particle that behaves like a tiny magnet.
- Many-body problem
- Predicting the behaviour of many interacting particles.
Learn more
Further reading
- Understanding Quantum Technologies 2025 (Olivier Ezratty, 8th edition, version 8.1 of 30 October 2025, arXiv:2111.15352 (v6), doi:10.48550/arXiv.2111.15352, CC BY-NC-ND 4.0)See Part 2: Computing hardware; Part 3: Computing software
- Understanding Quantum Technologies 2026 (Olivier Ezratty, 9th edition, version 9.0 of 17 October 2026 (latest edition))See Part 2: Computing hardware; Part 3: Computing software
Olivier Ezratty, Understanding Quantum Technologies (CC BY-NC-ND 4.0). Links only; no text of the book is reproduced on this portal.