We study the geometry of
the nullcone N = NV⊕k for several copies of a representation V of a reductive group
G and its behavior for different k. We show that for large k there is a certain
“stability” with respect to the irreducible components. In the case of the so-called
𝜃-representations, this can be made more precise by using the combinatorics of the
weight system as a subset of the root system. All this finally allows us to
calculate explicitly and in detail a number of important examples, such as
the cases of 3- and 4-qubits, which play a fundamental rôle in quantum
computing.