In open-pit mine planning, the design of the most profitable ultimate pit limit is a prerequisite to developing a feasible mining sequence. Currently, the design of an ultimate pit is achieved through a computer program in most mining companies. The extraction of minerals in open mining methods needs a lot of capital investment, which may take several decades. Before the extraction, the p...

Biphotons, generated from a hot atomic vapor via the process of spontaneous four-wave mixing (SFWM), have following merits: Stable and tunable frequencies as well linewidth. Such merits are very useful in application long-distance quantum communication. However, hot-atom SFWM biphoton sources previously had far lower values generation rate per linewidth, i.e., spectral brightness, compared with...