Schrödinger, Szilard, and the emergence of the EPR argument

Abstract

Einstein, Podolsky and Rosen’s “Can quantum mechanical description of reality be considered complete?”(1935) and Schrödinger’s “Die gegenwärtige Situation in der Quantenmechanik” (1936) are commonly accepted as the seminal papers for the modern study of quantum mechanical entanglement. However, not much has been known about the prehistory of these papers. We were able to trace the development of both Einstein’s and Schrödinger’s thought, using Schrödinger’s correspondence and especially his extensive research notes. We especially found that they both got important input from Leo Szilard, who proposed in 1931 a thought experiment that is a direct precursor to the EPR experiment and a quantum mechanical state that is essentially identical to the EPR state