The concept of "what separates" quantum fields is an interesting question, and it touches upon the nature of the underlying fabric of the universe. Currently, our understanding of the fundamental nature of reality is described by quantum field theory, which treats different types of particles as excitations of their respective quantum fields.
In this framework, each fundamental particle (such as electrons, quarks, photons, etc.) is associated with its own quantum field that permeates all of space and time. These fields are considered to be distinct entities with their own characteristics and interactions.
However, it is important to note that quantum field theory describes the behavior of these fields and particles, but it does not explicitly address the question of what lies beyond or interconnects these fields at a deeper level. Our current knowledge does not provide a definitive answer to this question.
Some theoretical frameworks, such as string theory and other approaches to quantum gravity, attempt to go beyond quantum field theory and propose a more fundamental description of the universe. These theories aim to provide a unified framework that encompasses all the fundamental forces and particles in a coherent way. However, these theories are still under active development and are far from being fully understood or experimentally confirmed.
In summary, while quantum field theory provides a powerful framework for understanding the behavior of particles and their associated fields, the question of what underlies or interconnects these fields at a more fundamental level remains an open area of research in theoretical physics.