Wen studied
superstring theory under theoretical physicist
Edward Witten at
Princeton University where he received his Ph.D. degree in 1987. He later switched his research field to
condensed matter physics while working with theoretical physicists
Robert Schrieffer,
Frank Wilczek,
Anthony Zee in
Institute for Theoretical Physics, UC Santa Barbara (1987–1989). Wen introduced the notion of topological order (1989) and quantum order (2002), to describe a new class of matter states. This opened up a new research direction in condensed matter physics. He found that states with topological order contain non-trivial boundary excitations and developed chiral
Luttinger theory for the boundary states (1990). Boundary states can become ideal conduction channels which may lead to device application of topological phases. He proposed the simplest topological order —
Z2 topological order (1990), which turns out to be the topological order in the
toric code. He also proposed a special class of topological order: non-Abelian quantum Hall states. They contain emergent particles with
non-Abelian statistics which generalizes the well known Bose and Fermi statistics. Non-Abelian particles may allow us to perform fault tolerant quantum computations. With Michael Levin, he found that
string-net condensations can give rise to a large class of topological orders (2005). In particular, string-net condensation provides a unified origin of
photons,
electrons, and other
elementary particles (2003). It unifies two fundamental phenomena:
gauge interactions and
Fermi statistics. He pointed out that topological order is nothing but the pattern of long range entanglements. This led to a notion of symmetry protected topological (SPT) order (short-range entangled states with symmetry) and its description by group cohomology of the symmetry group (2011). The notion of SPT order generalizes the notion of
topological insulator to interacting cases. He also proposed the SU(2) gauge theory of
high temperature superconductors (1996). ==Professional record==