The microverse, as coined by Dr. Ryan Choi and initially referred to as the atomverse by Ray Palmer, is a nanoscopic or possibly an even smaller dimension existing within the multiverse. It is accessible by shrinking to a nanoscopic or possibly an even smaller size, as the dimension is essentially invisible to the naked eye.
During the Anti-Monitor Crisis, Harrison Nash Wells, Ray, and Ryan Choi built a device that can eternally shrink an individual once activated. This invention was used on the Anti-Monitor, sending him to and trapping him in the microverse for all eternity, rendering him completely unable to affect the multiverse as he is perpetually shrinking.
- Mobius (perpetually shrinking)
DC's Legends of Tomorrow