Quantized charge fractionalization at quantum Hall Y junctions in the disorder dominated regime

Abstract

Fractionalization is a phenomenon where an elementary excitation partitions into several pieces. This picture explains non-trivial transport through a junction of one-dimensional edge channels defined by topologically distinct quantum Hall states, for example, a hole-conjugate state at Landau-level filling factor ν = 2/3. Here we employ a time-resolved scheme to identify an elementary fractionalization process; injection of charge q from a non-interaction region into an interacting and scattering region of one-dimensional channels results in the formation of a collective excitation with charge (1−r)q by reflecting fractionalized charge rq. The fractionalization factors, r = 0.34 ± 0.03 for ν = 2/3 and r = 0.49 ± 0.03 for ν = 2, are consistent with the quantized values of 1/3 and 1/2, respectively, which are expected in the disorder dominated regime. The scheme can be used for generating and transporting fractionalized charges with a well-defined time course along a well-defined path.

Characterization of quasiparticle tunneling in a quantum dot from temperature dependent transport in the integer and fractional quantum Hall regime

“…Relating excitation energy and crossover temperature via hv edge /L 3.53k B T act , we obtain the estimate v edge = 1.6 × 10 4 m/s. This is somewhat smaller than the recently reported edge velocities for plasmons of 5-8 × 10 4 m/s for a 2/3 edge and 2-4 × 10 4 m/s for a 1/3 edge, obtained in time-of-flight measurements of a charge wave package [61]. Interferometry experiments determined the edge velocity of integer edge modes to 0.5 − 2 × 10 5 m/s [35,62], which is larger than our value for fractional edge modes.…”

Plasmon modes of coupled quantum Hall edge channels in the presence of disorder-induced tunneling

“…In addition to these individually successful investigations of each system, it would be advantageous to coherently understand the two cases, because actual devices may involve both interaction and tunneling. Indeed, a recent high-frequency experiment supports the emergence of pure neutral and charge modes in the ν = 2 system in the presence of tunneling 20 . There may also be some cases where disorder-induced scattering is suppressed in the ν = 2/3 case.…”

“…One can investigate the eigenmodes by using timedomain experiments 6,12,20 . For example, by using the same device structure as that shown in Fig.…”

Influence of channel mixing in fermionic Hong-Ou-Mandel experiments

“…In particular, they are known to affect the propagation of an injected electronic wavepacket, leading to its decomposition into charge and neutral modes [16,29,33,[84][85][86]. This is an instance of charge fractionalization, a well-known phenomenon in various interacting one-dimensional systems [87][88][89][90][91][92].…”