What quantum computers are
Quantum computers use qubits, which exploit superposition and entanglement, to tackle certain problems in ways classical computers cannot. They are not faster general-purpose computers. They are specialised machines for specific classes of problem.
Where things stand
Today's devices are still limited by noise and errors. Error correction, which combines many physical qubits into more reliable logical qubits, is advancing quickly but is not yet at the scale needed for most valuable applications. Timelines are uncertain, so plans should not depend on a specific year.
Promising applications
- Simulation of molecules and materials, relevant to chemistry, batteries and drug discovery.
- Optimisation, where quantum and quantum-inspired methods are being explored for logistics and scheduling.
- Machine learning, an active research area with fewer proven advantages so far.
The one certain impact: cryptography
A large, error-corrected quantum computer could break the public-key cryptography used across the internet today. That is why Australian guidance sets the end of 2030 to stop using traditional asymmetric cryptography, and why the quantum-safe transition is the one quantum project every organisation should start now.
Three sensible actions
- Start the post-quantum cryptography transition with an inventory and roadmap.
- Build literacy in a small team that can assess claims and opportunities.
- Explore one use case in simulation or optimisation with a clear, low-cost experiment.