Energy-Information Coupling From Classical To Quantum

Arcangelo Rossi

Published 2002-11-12, updated 2003-05-29Version 3

It is known that there is no possibility of transmitting information without a certain amount of energy. This is arbitrarily small in Classical Physics, due to the continuous nature of the energy parameter, while one cannot reduce that amount below Planck's energy quanta in Quantum Physics. In short, one cannot send less than a photon from a place to another when transmitting a minimum of information. However, as single photons are never completely defined simultaneously in all their parameters as position and momentum, their exact contribution to the information transmitted cannot be known in advance, but only probabilistically predicted. So the information transmitted is always blurred before one can - in a way that is only probabilistically predictable - localize or, alternatively, determine the momenta of the photons transporting it. In order to enhance the information content of a message, is it then really possible to exploit the situation by considering the information contained in a superposition state before localization or, alternatively, determination of momenta? It would be so if such blurred information were richer than a defined one, the former being vaguer than the latter as it would be compatible with more possible outputs, and only in this sense more extensive. But if one defines the information content of a state as the negative logarithm of the probability of the state itself, it is not possible to identify the more a priori probable blurred information pertaining to that state with the bigger one. Then the idea of exploiting a supposedly enhanced information content of superposition states in Quantum Computation seems to contradict directly - but, as we will se, without necessity - the classical probabilistic definition of information.