The top comment mentions DARPA research, but for those who are actually interested in the theory behind the memristor and its potential applications, here [1] is an excellent resource by the man who discovered the first physical memristor.
Furthermore, there is a huge amount of open access journal articles and wikipedia material on memristors. DARPA is nowhere close to the cutting edge, SK Hynix is already tooling ReRAM fabs for mass production.
1. https://www.youtube.com/watch?v=bKGhvKyjgLY