1980 Paul Benioff described quantum mechanical Hamiltonian models of computers[2] Yuri Manin proposed an idea of quantum computing[3] 1981 Richard Feynman in his talk (and also in his famous lecture "There's Plenty of Room at the Bottom") at the First Conference on the Physics of Computation, held at MIT in May, observed that it appeared to be impossible in general to simulate an evolution of a quantum system on a classical computer in an efficient way. He proposed a basic model for a quantum computer that would be capable of such simulations[4] Paul Benioff gave talk at the conference, "Physics of Computation" held at MIT in May 1981. Talk title was "Quantum mechanical Hamiltonian models of discrete processes that erase their own histories: application to Turing machines".