Quantum ether: photons and electrons from a rotor model

  title={Quantum ether: photons and electrons from a rotor model},
  author={Michael Levin and Xiao-Gang Wen},
  journal={Physical Review B},
We give an example of a purely bosonic model--a rotor model on the 3D cubic lattice--whose low energy excitations behave like massless U(1) gauge bosons and massless Dirac fermions. This model can be viewed as a ''quantum ether;'' a medium that gives rise to both photons and electrons. It illustrates a general mechanism for the emergence of gauge bosons and fermions known as ''string-net condensation.'' Other, more complex, string-net condensed models can have excitations that behave like… 
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