The role of quantum decoherence in the understanding of optical isomerism

SEBASTIAN FORTIN; OLIMPIA LOMBARDI; JUAN CAMILO MARTÍNEZ GONZÁLEZ

Rio de Janeiro

Congreso; Annual Symposium 2015 of the International Society for the Philosophy of Chemistry; 2015

International Society for the Philosophy of Chemistry (ISPC)

In this work we will address the topic of optical isomerism and the challenges that it implies regarding the idea that chemistry, at the molecular level, can be explained by quantum mechanics. In this context, we will formulate with precision Hund?s paradox: since the eigenstates left and right of the chirality operator are not eigenstates of the Coulombian Hamiltonian, it is necessary to explain why those states are observed in the laboratory. Hund?s strategy consists in maintaining the Coulombian Hamiltonian, identifying the states left and right as superpositions of the eigenstates of the Hamiltonian, and then supplying a reason why the molecule does not decay to the ground state, eigenstate of the Hamiltonian. However, this strategy requires to admit the existence of an exceptional kind of molecules that are not in their ground states.At present, the most appealed solution is based on the phenomenon of quantum decoherence. However, the conceptual analysis of the theory of decoherence will allow us to conclude that, as well as decoherence does not solve the quantum measurement problem, the appeal to the diagonalization of the reduced state of the molecule in interaction with its environment is not sufficient to explain the definite value of chirality observed in laboratory. In particular, if chiral states are not eigenstates of the Hamiltonian and each molecule is in a superposition of both states, decoherence does not make such superposition disappear.