3/2 fractional quantum Hall plateau in confined two-dimensional electron gas

Abstract

Even-denominator fractional quantum Hall (FQH) states, such as 5/2 and 7/2, have been well known in a two-dimensional electron gas (2DEG) for decades and are still investigated as candidates of non-Abelian statistics. In this paper, we present the observation of a 3/2 FQH plateau in a single-layer 2DEG with lateral confinement at a bulk filling factor of 5/3. The 3/2 FQH plateau is quantized at $$\left( {\frac{h}{{e^2}}} \right)/\left( {\frac{3}{2}} \right)$$ h e 2 ∕ 3 2 within 0.02%, and can survive up to 300 mK. This even-denominator FQH plateau may imply intriguing edge structure and excitation in FQH system with lateral confinement. The observations in this work demonstrate that understanding the effect of the lateral confinement on the many-body system is critical in the pursuit of important theoretical proposals involving edge physics, such as the demonstration of non-Abelian statistics and the realization of braiding for fault-tolerant quantum computation.

Local incompressibility of fractional quantum Hall states at a filling factor of 3/2

“…Our experiments qualitatively support the transport measurements of a spatially confined 2DEG at ν = 3/2 [10]. The 2DEG incompressibility revealed by Zhang et al may occur due to the local incompressibility of the 3/2 fractional state and commensurability of the constriction in the confining potential with the size of one or few spin textures.…”

“…The first fractional quantum Hall state of this type, 5/2, was found in experiments on magnetotransport in highmobility two-dimensional GaAs/AlGaAs-based heterostructures [7,8]. More stable at first glance, fractional quantum Hall state at ν = 3/2 was not observed in GaAs until recently [9,10]. Here we do not consider intricate electron systems with complementary degrees of freedom: a layer index in double electron layers or a size-quantized subzone in wide quantum wells.…”

Quantum Confinement Effects on Excitonic Properties in the 2D vdW quantum system: The ZnO/WSe2 Case

“…Due to quantum confinement effects, the conventional bulk quantum well materials made from III-V semiconductors (such as, GaAs, InP, and their alloys) show many novel physical properties, such as strong quantum confined Stark effect, fractional quantum Hall effect, and room-temperature stimulated optical emission, which have enriched our knowledge about physical properties in bulk confined systems. [12][13][14] Thus, quantum confinement effects provide powerful ways to engineer the materials properties, such as electronic, optoelectronic, and photothermal properties in nanomaterials. It brings us the ability to design ultrathin optoelectronic devices, such as transistors and photodetectors.…”

Double-frequency Aharonov-Bohm effect and non-Abelian braiding properties of Jackiw-Rebbi zero-mode

“…Another peculiar property of the Jackiw-Rebbi zero-mode is the 1/2 charge fractionalization, which has been claimed [ 24 ] to be detectable in a pumping process [ 33 ] or by Coulomb blockade. Recently, a novel 3/2 FQH plateau is observed in single layer 2D electron gas with confined geometry [ 34 ]. Jackiw-Rebbi zero-mode induced by the confined geometry could be a tentative explanation [ 34 ] that similar mechanism has been proposed in QSHI [ 22 ].…”

“…Recently, a novel 3/2 FQH plateau is observed in single layer 2D electron gas with confined geometry [ 34 ]. Jackiw-Rebbi zero-mode induced by the confined geometry could be a tentative explanation [ 34 ] that similar mechanism has been proposed in QSHI [ 22 ].…”