They used a superconducting qubit-based approach called the "Sycamore" processor. Google continues to focus on improving its quantum processors, error correction techniques, and exploring applications in various fields.
Microsoft (Microsoft Quantum): Microsoft has been investing in quantum research through its Microsoft Quantum program. They are working on developing a topological qubit called the Majorana fermion, which could potentially be more robust against decoherence. Microsoft is also building a software platform called the Quantum Development Kit, which aims to enable developers to write and simulate quantum code. They are exploring partnerships with other organizations for research collaboration and are focused on developing a scalable quantum computer.
It's important to note that the field of quantum computing is highly complex and still in its early stages. Progress can vary, and it is difficult to make a definitive statement about one company's progress compared to another without up-to-date information. Each company has its own unique strengths, research directions, and areas of focus.
For the latest information on the progress of Microsoft, IBM, and Google in quantum computing, I recommend referring to their official websites, research papers, and news updates from reliable sources.