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Electron fractionalization in two-dimensional graphenelike structures

Chang-Yu Hou·Claudio Chamon·Christopher Mudry
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Abstract

Electron fractionalization is intimately related to topology. In one-dimensional systems, fractionally charged states exist at domain walls between degenerate vacua. In two-dimensional systems, fractionalization exists in quantum Hall fluids, where time-reversal symmetry is broken by a large external magnetic field. Recently, there has been a tremendous effort in the search for examples of fractionalization in two-dimensional systems with time-reversal symmetry. In this letter, we show that fractionally charged topological excitations exist on graphenelike structures, where quasiparticles are described by two flavors of Dirac fermions and time-reversal symmetry is respected. The topological zero-modes are mathematically similar to fractional vortices in p-wave superconductors. They correspond to a twist in the phase in the mass of the Dirac fermions, akin to cosmic strings in particle physics.

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Chang-Yu Hou, Claudio Chamon, Christopher Mudry. 2007-05-21. Electron fractionalization in two-dimensional graphenelike structures. https://doi.org/10.1103/physrevlett.98.186809

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