Industry & Era
Quantum Supremacy
The milestone at which a quantum computer performs a specific task faster than any classical computer could.
Definition
Quantum supremacy (also called quantum advantage in some contexts) refers to the point at which a quantum computer demonstrates the ability to perform a specific computation faster than the best available classical computers or supercomputers. The term was popularized after Google's 2019 announcement that its Sycamore processor had achieved this milestone for a specific mathematical sampling task.
Technical Definition
Google's 2019 claim involved random circuit sampling — a task with no direct practical application, but one that is believed to be exponentially hard for classical computers. The Sycamore chip's result was later challenged and partially rebutted by improved classical simulations, illustrating that 'supremacy' claims for specific tasks are often contested and that the boundary between 'hard for classical' and 'achievable quantumly' is still being defined.
Visual Explanation: An Analogy
Quantum supremacy is like a new type of runner completing a specific kind of race faster than any human — impressive and significant, but not the same as being better at all races. The task may be specially chosen to suit the quantum runner's strengths.
Real-World Use Cases
- Marking a historical milestone in quantum computing development
- Motivating further investment and research in quantum hardware
- Prompting debate about how to fairly measure and compare quantum and classical performance
Common Misconceptions
- Quantum supremacy on one specific task does not mean a quantum computer is generally more powerful than a classical computer for all tasks.
- The term 'supremacy' is sometimes replaced by 'quantum advantage' to avoid implying broader superiority.