Google Willow vs Xanadu Borealis Specs, Pricing & Performance [2026]
Quick Verdict
Google Willow uses Superconducting while Xanadu Borealis uses Photonic technology. Xanadu Borealis offers more physical qubits (216 qubits).
Specification Comparison
| Metric | Google Willow | Xanadu Borealis |
|---|---|---|
| Physical Qubits | 105 | 216 ✓ |
| Technology | Superconducting | Photonic |
| 2Q Gate Fidelity | 99.88% ✓ | — |
| 1Q Gate Fidelity | 99.97% ✓ | — |
| Readout Fidelity | 99.90% ✓ | 98.00% |
| Quantum Volume | — | — |
| CLOPS | 100,000 ✓ | — |
| T1 (Relaxation) | 100 µs ✓ | — |
| T2 (Dephasing) | 80 µs ✓ | — |
| 1Q Gate Time | 25 ns ✓ | — |
| 2Q Gate Time | 68 ns ✓ | — |
| Connectivity | Grid (deg 4) | Linear (deg 2) |
| Max Circuit Depth | 1,000 ✓ | 10 |
| Max Shots | 1,000,000 ✓ | 100,000 |
| Dynamic Circuits | No | No |
| Error Mitigation | Available | No |
| Cloud Platforms | 0 platforms | 2 platforms |
Green bold values with a checkmark indicate the better result for each metric.
Pricing Comparison
Example: 10-qubit, 50-depth circuit, 1,000 shots — estimated cost on cheapest platform: Google Willow: N/A vs Xanadu Borealis: $0.5000
Superconducting Google Willow
Photonic Xanadu Borealis
| Platform | Price | Status |
|---|---|---|
| Best Xanadu Cloud | $0.5000/task | Available |
| qBraid | $0.5000/task | Available |
Superconducting vs Photonic: Technology Tradeoffs
- Advantage
- Fast gate speeds (tens to hundreds of nanoseconds), mature fabrication technology using standard semiconductor processes, and strong industry investment make this the most commercially advanced platform.
- Challenge
- Requires dilution refrigerators operating near absolute zero (~15 mK), leading to large physical footprints and high infrastructure costs. Qubits are sensitive to noise, limiting coherence times to microseconds-to-milliseconds range.
- Gate Speed
- 10–700 ns per gate
- Fidelity
- 99.5–99.9% for 2-qubit gates
- Advantage
- Operates at room temperature (no cryogenics required), photons travel at the speed of light with minimal decoherence, and photonic hardware is compatible with existing fiber-optic telecommunications infrastructure for quantum networking.
- Challenge
- Deterministic photon-photon interactions are extremely difficult to engineer, making universal fault-tolerant quantum computation challenging. High photon loss rates and detector inefficiencies limit circuit depth. Current GBS machines are specialized rather than general-purpose.
- Gate Speed
- Picoseconds for passive operations; detector timing ~ns
- Fidelity
- Variable; loss-dominated; ~98% for single-photon detectors
Use Case Recommendations
Higher 2Q gate fidelity (99.88%) means fewer errors in VQE/UCCSD circuits.
More qubits (216 qubits) allows encoding larger problem instances.
Frequently Asked Questions
What is the difference between Google Willow and Xanadu Borealis?
Google Willow uses Superconducting while Xanadu Borealis uses Photonic technology. Xanadu Borealis offers more physical qubits (216 qubits). These QPUs use fundamentally different qubit technologies: Superconducting vs Photonic.
Which is better for quantum chemistry, Google Willow or Xanadu Borealis?
For quantum chemistry, gate fidelity is the most critical metric. Compare the 2Q gate fidelity figures in the spec table above to determine which QPU is better suited for your chemistry workload.
How do the prices compare between Google Willow and Xanadu Borealis?
Google Willow is available from no public cloud access. Xanadu Borealis is available from $0.5000/task on Xanadu Cloud. Note that pricing models differ — per-shot pricing is directly comparable while AQT and HQC models depend on circuit structure.
Which QPU has better connectivity, Google Willow or Xanadu Borealis?
Google Willow uses Grid connectivity (degree 4) while Xanadu Borealis uses Linear connectivity (degree 2).
What are the coherence times for Google Willow vs Xanadu Borealis?
Google Willow: T1=100 µs, T2=80 µs.
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