Magmatter

Magmatter is a form of exotic matter which is made up of extremely small atom-like particles, which themselves are made up of magnetic monopoles.

Normal atoms are about 100 to 200 picometers across. Magmatter atoms are about 5 billion times smaller than this and therefore magmatter is much denser than ordinary matter.

Because of the much higher binding energy (about 300 GeV) holding the atoms together, magmatter is about 1032 times stronger.

Magmatter materials have free breaking lengths of millions to billions of kilometers. This means that it has the tensile strength required to hold a megastructure like the Ringworld together.

Magmatter is relatively stable (compared to antimatter) and easy to handle when bound with conventional matter while still maintaining its useful properties of magnetic charge and great density.

Practical uses for the strength of magmatter requires the advanced control and logistics abilities of Type II civilizations. They are used in ultra-fine, hyper-strength cables and braces in megastructural engineering, and near-indestructible coatings for conversion drive rocket nozzles and massive military transports and weapons platforms.

Because of the density of magmatter, this leads to picoscale engineering and picotechnology. With sufficient advancements, femtotechnology is possible.