n 1935, at Princeton Institute of Higher Studies, Einstein, postdoctoral Rosen and researcher Podolski jointly completed the paper "Can the quantum mechanical description of physical reality be considered complete?", This paper was published in Physical Review in May. This is the first paper to discuss the counter intuitive prediction of quantum mechanics theory for strongly correlated systems. In this paper, they described EPR paradox in detail and tried to discuss the incomplete properties of quantum mechanics through an ideological experiment. They did not further study the properties of quantum entanglement.

After reading the EPR paper, Schrodinger had a lot of feelings. He wrote a letter to Einstein in German. In this letter, he first used the term Verschr ä nkung (he translated it as "entanglement"), which is to describe the relationship between two temporarily coupled particles that remain after they are no longer coupled in the EPR thought experiment. Shortly afterwards, Schrodinger published an important paper, giving a definition to the term "quantum entanglement", and researching and exploring related concepts. Schrodinger realized the importance of this concept. He showed that quantum entanglement is not only a very interesting property of quantum mechanics, but also a characteristic property of quantum mechanics; Quantum entanglement makes a complete cut between quantum mechanics and classical ideas. Like Einstein, Schrodinger was not satisfied with the concept of quantum entanglement, because quantum entanglement seemed to violate the speed limit set for information transmission in relativity. Later, Einstein ridiculed quantum entanglement as a ghostly action at a distance.