There was a time, back in the early days of computing, when we had vacuum tubes, relays, mechanical gears plus several different types of analog computers. We’re kind of in that same era today with quantum computers. We have analog quantum computers that can be used to solve very specific problems, and several different approaches to general purpose quantum computers, including those with semiconducting qubits, trapped ions, spin qubits, quantum dots, topological qubits, photonic qubits, neutral atom qubits — and many more. Each has its own strengths and weaknesses and use cases.
The options furthest along when it comes to actual real-world use cases are the analog quantum computers like those that use quantum annealing technology. This is useful for solving some quantum-related physics and optimization problems in a way similar to how a bathtub full of water can solve the problem of calculating the volume of an oddly-shaped physical object — such as, say, a crown. Eureka?
When it comes to the general-purpose quantum computers, the superconducting approach seems to be in the lead right now, according to Gartner analyst Chirag Dekate. “The physics is much better understood and it’s now an engineering problem, not a physics problem,” he says.
