Information in a sign is unambiguous: it is necessarily a single bit inside, but quite uncertain outside (depending on the utilized alphabet or vocabulary or even on all texts written by that alphabet or vocabulary).. The concept of sign needs and therefore generates a space between the necessity and unity of the sign and its arbitrariness and uncertainness among the elements of alphabet or vocabulary depending furthermore on all their uses (all words or texts recorded by means of them). The sign being always and moving in that space can be only partial, motivated by the unrealizable aspiration to complete ultimately the infinite process of signifying. Even much more: Saussure’s semiology is an implicit ontology as the being of all is what appears in that infinite process of signifying. Quantum mechanics had to resolve the problem of how to describe uniformly both quantum leaps and smooth motion, namely by the Schrödinger equation. It was reformulated thoroughly in terms of quantum information in the end of the 20th century. Though involved differently in quantum mechanics, quantum information can be equated unambiguously to the generalization of information to infinite sets and series. The Schrödinger equation itself can be also exhaustedly interpreted in terms of quantum information. That latter interpretation links it to Saussure’s tension of the sign generating an implicit ontology as semiology. Then the Schrödinger equation can be seen as a solution of the problem above about the relation of information and Saussure’s sign: both “arbitrary sign” outside and corresponding quantum information are equated to both “necessary sign” inside and corresponding information.