Here is the list of top 6 companies (and related pages) to watch out in quantum computing space in the year 2018 and later. You would want to bookmark the pages given below in order to follow their work in the area of quantum computing from time-to-time.
- D-wave: D-Wave quantum computers are based on superconducting processor that uses quantum mechanics to massively accelerate computation. Here is the link to technology overview of their quantum computer.
- Rigetti: Rigetti is building hardware and software with fundamentally new integrated circuits that store and process quantum information.
- IBM Quantum Computing: IBM is on the forefront of quantum computing and they are making their quantum computing availabile through IBM cloud. Here is the page with greater details for learning IBM quantum computing