Quantum ether: photons and electrons from a rotor model

  title={Quantum ether: photons and electrons from a rotor model},
  author={Michael A. 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… Expand
From New States of Matter to a Unification of Light and Electrons(Yukawa International Seminar 2004 (YKIS2004) Physics of Strongly Correlated Electron Systems)
For a long time, people believe that all possible states of matter are described by Landau symmetry-breaking theory. Recently we found that string-net condensation provide a mechanism to produceExpand
An odyssey in modern quantum many-body physics
This thesis is a collection of research work in quantum many-body physics that I have done during the past few years. The topics include: 1. a theory of anomalous magnetotransport from massExpand
Emergent gauge symmetries -- making symmetry as well as breaking it
Gauge symmetries play an essential role in determining the interactions of particle physics. Where do they come from? Might the gauge symmetries of the Standard Model unify in the ultraviolet orExpand
Group field theory as the microscopic description of the quantum spacetime fluid: a new perspective on the continuum in quantum gravity
We introduce the group field theory (GFT) formalism for non-perturbative quantum gravity, and present it as a potential unifying framework for several other quantum gravity approaches, i.e. loopExpand
Emergence of helicity ±2 modes (gravitons) from qubit models
Abstract We construct two quantum qubit models (or quantum spin models) on three-dimensional lattice in space, L-type model and N-type model. We show that, under a controlled approximation, all theExpand
All-fermion electrodynamics and fermion number anomaly inflow
We demonstrate that 3+1-dimensional quantum electrodynamics with fermionic charges, fermionic monopoles, and fermionic dyons arises at the edge of a 4+1-dimensional gapped state with short-rangeExpand
Four revolutions in physics and the second quantum revolution — A unification of force and matter by quantum information
  • X. Wen
  • Physics
  • International Journal of Modern Physics B
  • 2018
Newton’s mechanical revolution unifies the motion of planets in the sky and the falling of apples on Earth. Maxwell’s electromagnetic revolution unifies electricity, magnetism, and light. Einstein’sExpand
Nonperturbative definition of the standard models
The Standard Models contain chiral fermions coupled to gauge theories. It has been a long-standing problem to give such gauged chiral fermion theories a quantum non-perturbative definition. ByExpand
Magnetic monopoles in spin ice
This work proposes that magnetic monopoles emerge in a class of exotic magnets known collectively as spin ice: the dipole moment of the underlying electronic degrees of freedom fractionalises into monopoles, which would account for a mysterious phase transition observed experimentally in spin ice in a magnetic field. Expand
Quantum spin ice: a search for gapless quantum spin liquids in pyrochlore magnets.
The latest developments in the study of a quantum spin liquid are described, focusing on the spin liquid phenomenology and the kinds of materials where such a phase might be found. Expand


Colloquium: Photons and electrons as emergent phenomena
Recent advances in condensed-matter theory have revealed that new and exotic phases of matter can exist in spin models (or more precisely, local bosonic models) via a simple physical mechanism, knownExpand
Quantum order from string net condensations and origin of light and massless fermions
Recently, it was pointed out that quantum orders and the associated projective symmetry groups can produce and protect massless gauge bosons and massless fermions in local bosonic models. In thisExpand
Origin of gauge bosons from strong quantum correlations.
  • X. Wen
  • Physics, Medicine
  • Physical review letters
  • 2002
Through models, it is shown that the existence of light can simply be a phenomenon of quantum coherence in a system with many degrees of freedom. Expand
Fermions, strings, and gauge fields in lattice spin models
We investigate the general properties of lattice spin models with emerging fermionic excitations. We argue that fermions always come in pairs and their creation operator always has a stringlikeExpand
String-net condensation: A physical mechanism for topological phases
We show that quantum systems of extended objects naturally give rise to a large class of exotic phases---namely topological phases. These phases occur when extended objects, called ``string-nets,''Expand
Quantum Field Theory of Many-body Systems: From the Origin of Sound to an Origin of Light and Electrons
1. Introduction 2. Path integral formulation of quantum mechanics 3. Interacting boson systems 4. Free fermion systems 5. Interacting fermion systems 6. Quantum gauge theories 7. Theory of quantumExpand
Hamiltonian Formulation of Wilson's Lattice Gauge Theories
Wilson's lattice gauge model is presented as a canonical Hamiltonian theory. The structure of the model is reduced to the interactions of an infinite collection of coupled rigid rotators. TheExpand
Artificial light and quantum order in systems of screened dipoles
The origin of light is an unsolved mystery in nature. Recently, it was suggested that light may originate from a new kind of order, quantum order. To test this idea in experiments, we study systemsExpand
Pyrochlore photons: The U ( 1 ) spin liquid in a S = 1 2 three-dimensional frustrated magnet
We study the $S=1/2$ Heisenberg antiferromagnet on the pyrochlore lattice in the limit of strong easy-axis exchange anisotropy. We find, using only standard techniques of degenerate perturbationExpand
Topological Order and Conformal Quantum Critical Points
Abstract We discuss a certain class of two-dimensional quantum systems which exhibit conventional order and topological order, as well as quantum critical points separating these phases. All of theExpand