Quantum Hardware Database
Google Sycamore
Google Sycamore achieved global recognition in 2019 when Google claimed it had achieved 'quantum supremacy' — completing a random circuit sampling task in 200 seconds that Google estimated would take the world's best supercomputer approximately 10,000 years. The claim was later contested, but Sycamore remains a landmark in quantum computing history.
Qubit Count
53
Qubit Type
Superconducting (transmon qubits)
Architecture
2D grid with nearest-neighbor connectivity
Released
2019
Gate Error (2Q)
~0.6% per two-qubit gate (at time of release)
Coherence Time
T₁ ~50 µs, T₂ ~70 µs (at time of release)
Operating Temp
~20 millikelvin
Cloud Access
Not publicly available
Company
Google (Google Quantum AI)
Connectivity
2D rectangular grid — each qubit connects to 4 nearest neighbors
Key Features
- First processor associated with a credible 'quantum supremacy' claim
- Programmable superconducting processor with 53 active qubits (54 qubits fabricated, one non-functional)
- 2D grid architecture enabling nearest-neighbor two-qubit gates
- Demonstrated random circuit sampling at scale
Limitations
- IBM and others later argued classical simulation of Sycamore's task was achievable in days, not 10,000 years, with improved classical algorithms
- Not available for public cloud access
- Relatively low qubit count and shorter coherence times by today's standards
Technical Notes
The 'quantum supremacy' debate around Sycamore highlighted a key challenge in benchmarking: as classical simulation algorithms improve, the threshold for what counts as 'hard for a classical computer' shifts. The scientific value of the demonstration was in proving large-scale superconducting control, not the specific task chosen.