Picotechnology / Picotech
There are many technologies that produce effects at the picoscale (1e-12 meters), but 'picotech' is a particular term, analogous to 'nanotech'. Users of the word imagine a technology or set of technologies that rearranges matter on the picoscale with something analogous to nanotechnology's scope and precision. It would supposedly allow not only precision arrangement of atoms but even arrangement of their internal states, leading not only to enhanced control over natural chemical reactions but to the creation of entirely novel atoms and molecules, including some stable and useful forms of exotic matter. Picotechnology in this sense is largely fictional. For reasons well embedded in physics, nothing approaching the characteristics of nanotechnology, with its precision control, complexity, and ability to produce larger scale or self-replicating structures, is possible at the picoscale.
Magmatter
Magmatter is the exception that proves the rule: while magmatter 'molecules' are at more or less the picoscale, and while magmatter has a number of extraordinary uses, the resulting materials and effects have only certain specific interactions with ordinary matter and only so much of it can even be gathered in one place without producing a singularity. Other 'picotech' effects and materials are even more limited in scope, despite important niche uses. Despite this, the term 'picotech' persists. One usage is as a synonym for clarketech, since picotech would presumably produce some similarly magical effects. 'Picotech' is also sometimes used in works of fantasy and science fiction, or features in popular superstition and rumours, but it is not experienced in this universe outside of some virch worlds.
See also FTL, time travel, femtotech.