Quantum Information: The New Frontier

Quantum information and computation is the new hype in physics. It is promising, mindboggling and even already applicable in cryptography, with good prospects ahead. A brief, rather subjective outline is presented. 1 Is Nature telling us something? Friends in experimental physics tell me that the essence of their observations are clicks in some counter. There is a click or there is none. This is experimental physics in a nutshell. There may be some magic in properly designing experiments and some magic in interpreting those clicks, but that is all there is. A single click represents some elementary physical proposition. It is also an answer to a question which might not even have been posed consciously. It is tempting to state that “Nature wants to tell us something” with these clicks about some formal structures, symmetries, music or numbers beyond the phenomena. Maybe that is the case, and most physicists tend to believe so; but maybe we are just observing crap, erratic emanations devoid of any meaning [1]. Anyway, we have to deal with those clicks, and one way to deal with them is to interpret them as information. For example, in an experimental inputoutput scheme, information is received, transformed and communicated by