Exploring Quantum Computing for PhD -where to start and what to research?

I’m from a computer science background and recently got interested in quantum computing. I’m looking for free resources (courses, videos or docs) to start learning the basics. Also I’m planning my PhD and wondering what research areas in quantum computing are exciting or have good scope like quantum cryptography or quantum ML Would love any tips, links or advice from people already in this field. Thanks! submitted by /u/BusyOpposite1723 [link] [comments]