The name for the graphics card technology that may come after Nvidia's in-development Volta range may be called Ampere. Although unconfirmed by Nvidia in any official capacity, German IT site Heise (via PCGN) suggested as such when it perused through an Nvidia earnings report.
"Information on the upcoming GPU generation, which should appear under the name ‘Ampere’, should be at the GPU Technology Conference 2018," the report reads.
Considering that that name appears to be a reference to famous scientist, André-Marie Ampère, that would certainly make sense for Nvidia's recent naming conventions. Volta is a reference to Italian physicist Alessandro Volta, Blaise Pascal was the inspiration for the Pascal generation, and so on. Similar to the way Intel has developed a penchant for naming its processors after famous lakes.
What we don't know is whether this naming announcement means that Ampere as a technology will leapfrog Volta, because 2018 is the expected launch date of the next Nvidia GPU technology. If that's when Ampere will make its appearance, what happens to Volta? It could be that Volta shows up early in 2018 and Ampere is merely debuted later in the year, but that would dampen the impact of Volta considerably. People are unlikely to pay out for a new GPU if they know another new range is just around the corner, even if it's to take advantage of the probable price drop of existing cards.
PCGamesN suggests that it could be that Volta becomes an AI and enterprise-focused graphics cards range, while Ampere is the new consumer technology.
Regardless, we'll have to wait to find out more before we know for sure.