Also, why is Microsoft placing such an emphasis on topological qubits when most other companies seem to be focusing on other qubit technologies?
I know topological qubits could handle noise far better than other systems, so they are appealing, but they are also new and seemingly only theoretical so far.
Microsoft is the only company that is trying to build a topological quantum computer. You mention that topological qubits handle noise far better than other systems, but they are also theoretical. That's the reason Microsoft is applying a topological approach. It's high-risk, high-reward. If Microsoft manages to realize a topological qubit, scaling up a computer made of topological qubits will be easier than competing approaches because a topological quantum computer would use less resources to perform quantum error correction compared to other implementations.
Nokia Bell Labs are doing some research for topological quantum computing. Their research makes interesting claims about replicable states stable for hours.
