 The study presents a series of quantum states characterized by dark solitons of the non-linear Schrodinger equation for a one-dimensional Bose gas interacting through repulsive delta function potentials. These classical solutions satisfy periodic boundary conditions and are called classical dark solitons. Exact solutions show that in the weak coupling case, the quantum and classical density profiles completely overlap with each other at initial and later times, and move together with the same speed. The matrix element of the bisonic field operator between the quantum states has the same profiles of square amplitude and phase as the classical complex scalar field of a classical dark soliton, and the corresponding profiles move together for a long period of time. It is suggested that these properties hold rigorously in the weak coupling limit. Additionally, the lifetime of the dark soliton-like density profile in the quantum state becomes infinitely long as the coupling constant approaches zero, by comparing it with the quantum speed limit time. Thus, the study calls these quantum states quantum dark soliton states. This article was offered by Jun Sotto, Rina Kanamoto, Irico Kaminishi, and others. We are article.tv, links in the description below.