A guide to the six major approaches to building quantum computers

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IBM and IonQ take fundamentally different physical approaches to quantum computing, with IBM using superconducting circuits cooled to about 15 millikelvin, colder than deep space, while IonQ traps individual charged atoms using electromagnetic fields. A new guide from The Quantum Insider breaks down six major hardware approaches, superconducting, trapped ion, photonic, neutral atom, topological and quantum annealing, noting that qubit count alone doesn't tell the full story since a system with 1,000 noisy qubits can be less useful than one with 50 more reliable ones

Superconducting qubits, used by IBM, Google and Rigetti, benefit from manufacturing compatibility with existing chip fabrication but suffer from short coherence times measured in microseconds. Trapped ion systems from IonQ and Quantinuum achieve high gate fidelity, with IonQ reporting 99.99 percent two qubit gate fidelity, but scale more slowly since adding ions to a single trap gets harder to control. Photonic systems from Xanadu and PsiQuantum resist decoherence well and suit quantum networking, though photons are genuinely difficult to entangle with each other for two qubit operations

Neutral atom systems from QuEra and Atom Computing show real scaling potential, with a Caltech team demonstrating a 6,100 qubit array in 2025, while Microsoft's topological approach using exotic Majorana particles remains experimental and has faced real scrutiny from the physics community over its verification methods. The guide concludes there may not be one single winning approach, with different hardware types likely serving different applications. Curious which specific approach people think is actually most likely to reach genuinely practical fault tolerant computing first

Types of Quantum Computers: 6 Major Quantum Computing Approachesthequantuminsider.com