Six Paths Toward Useful Quantum Computing
Quantum hardware is not a single technology. Each architecture encodes qubits in different physical systems — each with distinct advantages, limitations, and workload characteristics. No single approach has yet demonstrated clear supremacy for all tasks.
The Six Architectures
Compare the six major quantum computing hardware approaches. Each card shows the physical mechanism, key advantage, and primary limitation.
Architecture Comparison
Direct comparison requires care — different architectures are optimized for different tasks. See individual architecture pages for detail.
Data sourced from manufacturer documentation and published research as of 2026.
| Superconducting | Trapped Ion | Neutral Atom | Photonic | Annealing | Topological | |
|---|---|---|---|---|---|---|
| Qubit Medium | Josephson junctions (transmon) | Atomic ions (Yb-171, Ba-137) | Neutral atoms (Rb-87, Cs-133) | Photons in waveguides | Flux qubits | Majorana modes (research) |
| Control | Microwave pulses | Laser / microwave | Lasers (Rydberg) | Beam splitters, phase shifters | Magnetic flux annealing | Anyon braiding |
| Operating Temp. | ~15 mK | UHV, room temp trap | ~1–10 µK atoms | Room temp (SNSPD ~1 K) | ~15 mK | ~100 mK |
| Gate Speed | 10–500 ns | 1 µs – 1 ms | 100 ns – 10 µs | ns (optical path) | 1–2000 µs (anneal) | Not yet characterized |
| Connectivity | Fixed nearest-neighbor | All-to-all (within chain) | Reconfigurable | Reconfigurable | Sparse fixed (Pegasus/Zephyr) | TBD |
| Current Scale | 100–1000 physical qubits | 20–56 #AQ | 100–1000+ atoms | GBS only (no gate-based) | 5000–7000+ qubits | Research phase |
| Coherence | T1/T2: 50–500 µs | Seconds to minutes | Seconds (hyperfine) | Photons don't thermalize | ms (anneal window) | Theoretically protected |
| Scaling Approach | Larger chips, modular links | Photonic inter-chain links | Larger tweezer arrays | Silicon photonics fabs | Denser coupler graphs | Topological networks |
| Leading Companies | IBM, Google, Rigetti, IQM | IonQ, Quantinuum | QuEra, PASQAL, Atom Computing | PsiQuantum, Xanadu | D-Wave | Microsoft |
| Commercial Status | Cloud available | Cloud available | Cloud available (limited) | Boson sampling only | Cloud available | Research only |
Architecture Choice Matters for Your Workload
Architecture selection significantly affects which algorithms you can run and at what fidelity. Trapped-ion systems excel at high-fidelity deep circuits; superconducting systems offer throughput; neutral-atom systems enable large-scale analog simulation. Our workload compatibility guide maps 12 use cases across all six architectures.