Xiao-Gang Wen Home Page

String-net condensation -- a unification of light and electrons Q: What are light and fermions? A: Light is a fluctuation of closed strings of arbitrary sizes. Fermions are ends of open strings. Q: Where do light and fermions come from? A: Light and fermions come from the collective motions of string-like objects that form nets and fill our vacuum. Q: Why do light and fermions exist? A: Light and fermions exist because our vacuum is a quantum liquid of string-nets. (For details, click a talk (pdf) and Theory of everything (for some universes) )

Articles and lecture notes

• The universe is a string-net liquid -- an article in New Scientist (podcast)
• New states of matter and a unification of light and electrons -- an introduction (pdf)
  (The introduction chapter of a book that I am writing)
• An introduction to topological order (pdf)
• An introduction to quantum order, string-net condensation, and emergence of light and electrons (pdf)
• Tensor category theory of string-net condensation (pdf)
  (may be regarded as the chapter 11 of the book)

Talks

• String-net condensation (with java simulations) (html)
• An origin of light and electrons -- a unification of gauge interaction and Fermi statistics (pdf)
• A unification of light and electrons (pdf)
  a talk given in Celebration of T.D. Lee's 80th Birthday and the 50th Anniversary of the Discovery of Parity Non-conservation
  
• A KITPC talk on FQH state and topological orders (pdf)

Recent Publications

• A lattice bosonic model as a quantum theory of gravity (pdf)
  Zheng-Cheng Gu and Xiao-Gang Wen
  gr-qc/0606100
  Constructed a quantum spin model on a lattice which gives rise to emergent gravitons.
 
• A unification of light and electrons through string-net condensation in spin models (pdf)
  Michael A. Levin and Xiao-Gang Wen
  cond-mat/0407140
  String-net condensation provides a way to unify light and electrons.
 
• A fully fermionic mean field theory of the cuprate superconductors (pdf)
  Tiago C. Ribeiro, Xiao-Gang Wen
  cond-mat/0410750
  Introduced a new mean field theory of the tJ model, starting with electrons and spinons. The holons are bound states of an electron and an spinon.
  Recovered the phase diagram of the cuprates and explained the evolution of the electron spectral function from the undoped insulator to the overdoped Fermi metal.
  
 
• Doping a Mott Insulator: Physics of High Temperature Superconductivity (pdf 3.4Mb)
  Patrick A. Lee, Naoto Nagaosa, Xiao-Gang Wen
  cond-mat/0410445
  A review of the SU(2) slave-boson theory of high Temperatur superconductors.
  
 

Publications

• Theory of quantum order and string-net condensation
• Theory of everything (for some universes)
• Theory of topological order
• Topological order and quantum computation
• Gauge theory of high Tc superconductors
• Theory of fractional quantum Hall edge state
• Superfluidity/superconductivity in double-layer quantum Hall systems
• Topological superfluids

Java Simulations

Current and previous students

• Michael Levin, Student, Dept. of Physics, MIT
• Bas Overbosch, Student, Dept. of Physics, MIT
• Ying Ran, Student, Dept. of Physics, MIT
• Tiago Ribeiro, Student, Dept. of Physics, MIT
• Anna Lopatnikova, graduated
• Walter Rantner, Institute of Theoretical Physics, Univ. Innsbruck
• Sven Heemeyer, graduated
• Joel Moore, Professor, Dept. of Physics, University of California, Berkeley
• Claudio Chamon, Professor, Dept. of Physics, Boston University.
• Yong-Baek Kim, Professor, Dept. of Physics, University of Toronto.