Taming electronic decoherence in 1D chiral ballistic conductor*

Decoherence and relaxation of single-electron excitations induced by strong effective screened Coulomb interactions in Quantum Hall edge channels are an important challenge for the applications of electron quantum optics in quantum information and quantum sensing. We present a complete study of intrinsic single-electron decoherence within an ideal single-electron channel with long-range effective Coulomb interactions to determine the influence of the material and sample properties [Phys. Rev. B 98, 155302 (2018)]. We find that weak-coupling materials characterized by a high velocity of hot-electron excitations such as graphene may offer interesting perspectives for limiting intrinsic decoherence due to electron/electron interactions compared to lower velocity materials such as AlGaAs/AsGa. We discuss quantitively how extrinsic decoherence due to the coupling with the channel's electromagnetic environment can be efficiently inhibited in specifically designed samples at filling fraction two with one closed edge channel and we propose a realistic geometry for testing decoherence control in a Hong Ou Mandel experiment.