Quantum physics
Quantum physics was the branch of physics that used quantum theory to predict or explain the behavior of matter on the quantum level. 

Anaanda Ziff was awarded the Daystrom Award for quantum physics on stardate 46512.6. ()

In explaining the concept of quantum realities, Data explained that "for any event, there is an infinite number of possible outcomes. Our choices determine which outcomes will follow." Data then referred to "theory in quantum physics that all possibilities that can happen, do happen in alternate quantum realities." ()

Doctor Phlox, an expert in medicine and psychiatry, was not specialized in quantum physics. This fact made it difficult to give  a proper prognosis after his arm was apparently cloaked. ()

See also 
 Quantum astrophysics
 Quantum mechanics
Physics