Laughlin anyon complexes with Bose properties

Abstract

Two-dimensional electron systems in a quantizing magnetic field are regarded as of exceptional interest, considering the possible role of anyons—quasiparticles with non-boson and non-fermion statistics—in applied physics. To this day, essentially none but the fractional states of the quantum Hall effect (FQHE) have been experimentally realized as a system with anyonic statistics. In determining the thermodynamic properties of anyon matter, it is crucial to gain insight into the physics of its neutral excitations. We form a macroscopic quasi-equilibrium ensemble of neutral excitations - spin one anyon complexes in the Laughlin state ν = 1/3, experimentally, where ν is the electron filling factor. The ensemble is found to have such a long lifetime that it can be considered the new state of anyon matter. The properties of this state are investigated by optical techniques to reveal its Bose properties.

Birotons and “Dark” Quantum Hall Hierarchies

“…The authors of the paper observed analogous abnormal optical transitions in the spectrum of spin density neutral excitations for the main Laughlin state 1/3, measured by the resonant reflection for several heterostructures with GaAs/AlGaAs quantum wells [5,26,27]. The spectrum indicates the direct optical transitions that excite spin birotons (spin magnetogravitons), as well as the transitions that give rise to excitations with the energy lying in the bandgap of the fractional Hall dielectric ν = 1/3 (Figure 3).…”

“…The spectrum indicates the direct optical transitions that excite spin birotons (spin magnetogravitons), as well as the transitions that give rise to excitations with the energy lying in the bandgap of the fractional Hall dielectric ν = 1/3 (Figure 3). Unlike birotons, which exhibit bosonic properties predicted for neutral excitations [5], the anomalous excitations do not show signs of Bose statistics [26,27], suggesting possible transitions between the ground states of different fractional states rather than neutral excitations in the fractional QHE state 1/3.…”

“…(b) Energies of neutral excitations with spin 1 (S = 1) for the Laughlin state 1/3 calculated for spin birotons and spin excitons with zero momentum, at a magnetic field of 10 T (black dots). The green dots show the measured excitation energies from [5,6,25]. Red ovals indicate the corresponding pairs of experimental and calculated neutral excitations, SE(0)-spin exciton [6] and SBMR(0)-spin biroton (magneto-graviton) [5].…”

“…The green dots show the measured excitation energies from [5,6,25]. Red ovals indicate the corresponding pairs of experimental and calculated neutral excitations, SE(0)-spin exciton [6] and SBMR(0)-spin biroton (magneto-graviton) [5]. Squares mark the experimentally observable excitations that have no theoretical counterpart.…”

“…At present, the FQHE states with non-abelian anyons in the fractional states of 5/2 and 12/5 have been the focus of intense research [3,4]. In addition to single anyons, multiparticle anyon complexes have been observed, and their collective properties have been investigated [5]. In the very near future, further advancements in the experimental methods of studying anyon matter may well enable the observation of quasiparticles with more sophisticated abelian and non-abelian statistics than that of π/3.…”