Parafermion braiding in fractional quantum Hall edge states with finite chemical potential

ORAL

Abstract

Parafermions are non-Abelian anyons which generalize Majorana fermions and hold great promise for topological quantum computation. We study the braiding of Z2n parafermions which have been predicted to emerge as bound states in fractional quantum Hall systems at filling factor ν=1/n (n odd). Using a combination of bosonization and refermionization, we calculate the energy splitting as a function of distance and chemical potential for a pair of parafermions separated by a gapped region. Braiding of parafermions in quantum Hall edge states can be implemented by repeated fusion and nucleation of parafermion pairs. We simulate the conventional braiding protocol of parafermions numerically, taking into account the finite separation and finite chemical potential. We show that a nonzero chemical potential poses challenges for the adiabaticity of the braiding process because it leads to accidental crossings in the spectrum. To remedy this, we propose an improved braiding protocol which avoids those degeneracies.

*The authors acknowledge support by the National Research Fund, Luxembourg under grants ATTRACT 7556175, INTER 11223315, AFR 11224060 and PRIDE/15/10935404, as well as by Würzburg-Dresden Cluster of Excellence in Complexity and Topology in Quantum Matter.

Presenters

  • Thomas Schmidt

    • University of Luxembourg
    • University of Luxembourg Limpertsberg
    • Physics and Materials Research Science Unit, University of Luxembourg

Authors

  • Solofo Groenendijk

    • University of Luxembourg
  • Alessio Calzona

    • University of Luxembourg
    • University of Wurzburg
  • Hugo Tschirhart

    • University of Luxembourg
  • Edvin Idrisov

    • University of Luxembourg
  • Thomas Schmidt

    • University of Luxembourg
    • University of Luxembourg Limpertsberg
    • Physics and Materials Research Science Unit, University of Luxembourg