Photonic vs Superconducting Quantum Computers: What's the Difference?

When people think of quantum computing, they often picture the large chandelier-like structures of superconducting quantum computers. But there's another approach gaining significant momentum: photonic quantum computing. In this article, we'll explore how these two technologies differ and why each has its place in the quantum landscape.

Two Paths to Quantum Computing

Both superconducting and photonic quantum computers aim to harness quantum mechanical effects for computation, but they take fundamentally different approaches to creating and manipulating qubits.

Superconducting Quantum Computers

Superconducting quantum computers, developed by IBM, Google, and others, use electrical circuits made from superconducting materials. These circuits must be cooled to approximately 15 millikelvin—about 200 times colder than outer space—to exhibit quantum behaviour.

Key characteristics of superconducting systems include fast gate operations (nanosecond timescales), strong qubit-qubit interactions for implementing two-qubit gates, and mature fabrication using semiconductor manufacturing techniques. However, they require expensive dilution refrigerators and consume significant power for cooling.

Photonic Quantum Computers

Photonic quantum computers use particles of light (photons) as qubits. Because photons don't interact strongly with their thermal environment, these systems can operate at room temperature.

Companies like Xanadu, PsiQuantum, ORCA Computing, Quandela, and QuiX Quantum are advancing photonic approaches. Their systems offer inherent noise resistance (photons are naturally isolated from environmental disturbances), native compatibility with fibre optic networks for quantum communication, and no requirement for cryogenic cooling.

Side-by-Side Comparison

Which Is Better?

The honest answer: neither is universally better. Each technology excels in different contexts.

Superconducting systems currently lead in qubit count and have demonstrated quantum advantage in specific computational tasks. Their fast gate times and strong qubit interactions make them well-suited for certain algorithms. Major cloud providers offer access to superconducting quantum computers.

Photonic systems shine in scenarios where room-temperature operation, networking, or integration with optical communication is important. They're particularly promising for quantum communication, quantum sensing, and applications where the overhead of cryogenic cooling is prohibitive.

Why Photonics for Education?

For educational settings, photonic approaches offer compelling advantages. Without the need for cryogenic cooling, institutions can operate quantum hardware without multi-million dollar refrigeration systems. Students can physically interact with the hardware in a normal laboratory environment. The desktop scale makes deployment feasible for universities that don't have dedicated quantum facilities.

This is why Quantonic focuses on photonic platforms: we believe accessible hardware will accelerate quantum education and prepare the next generation of quantum scientists and engineers.

The Future Is Hybrid

Looking ahead, the quantum computing landscape will likely include both technologies—and others. Trapped ions, neutral atoms, and topological approaches each have their own advantages. The most practical quantum systems may even combine multiple technologies, using each where it excels.

What matters most isn't which technology "wins"—it's ensuring that researchers, students, and innovators have access to quantum hardware so they can explore, learn, and build the quantum future.