Goals one wants to achieve with those two theories are similar.

We know that superstring theory is a potential theory of everything. One may want to ask what is the difference between the string-net-liquid approach and the superstring approach?

Our understanding of the superstring theory has been evolving. According to an early understanding of the superstring theory, all the elementary particles correspond to small segments of superstrings. Different vibration modes of a small superstring result in different types of elementary particles.

The above point of view is very different from that of the string-net liquid. According to the string-net picture, everything comes from simple qubits that form the space. The qubits fill the whole space, and the qubits are the space. No qubits no space. The string-nets are fromed by the "1" qubits. The strings can be as long as the size of universe. Light (photons) correspond to the collective motion of the string-nets that fill the space and an electron corresponds to a single end of string. (See a picture of string-net "vaccum". See also a talk)

A modern understanding of the superstring theory is still under development. According to Witten, one of the most important questions in superstring theory is to understand what is superstring. So at this time, it is impossible to compare the modern understanding of the superstring theory with the string-net theory. In particular it not clear if the superstring theory can be viewed as a local bosonic system (ie a qubit system). The string-net theory is fundamentally a local bosonic system (ie a qubit system).

So, if superstring theory is a qubit model (or a quantum spin model in condensed matter physics), then superstring theory and the string-net theory is the same, since the string-net theory is a qubit model (or a quantum spin model in condensed matter physics).

This post imported from StackExchange Physics at 2014-03-17 03:21 (UCT), posted by SE-user Xiao-Gang Wen