Experimental studies of the fractional quantum Hall effect in the first excited Landau level

Abstract

We present a spectrum of experimental data on the fractional quantum Hall effect (FQHE) states in the first excited Landau level, obtained in an ultrahigh mobility two-dimensional electron system (2DES) and at very low temperatures and report the following results: For the even-denominator FQHE states, the sample dependence of the nu=5/2 state clearly shows that disorder plays an important role in determining the energy gap at nu=5/2. For the developing nu=19/8 FQHE state the temperature dependence of the Rxx minimum implies an energy gap of ~5mK.The energy gaps of the odd-denominator FQHE states at nu=7/3 and 8/3 also increase with decreasing disorder, similar to the gap at 5/2 state. Unexpectedly and contrary to earlier data on lower mobility samples, in this ultra-high quality specimen, the nu=13/5 state is missing, while its particle-hole conjugate state, the nu=12/5 state, is a fully developed FQHE state. We speculate that this disappearance might indicate a spin polarization of the nu=13/5 state. Finally, the temperature dependence is studied for the two-reentrant integer quantum Hall states around nu=5/2 and is found to show a very narrow temperature range for the transition from quantized to classical value.

to be published

References in corpus (6)

• Non-Abelian Anyons and Topological Quantum Computation
• Particle-hole symmetry and the Pfaffian state
• Particle-Hole Symmetry and the $\nu =5/2$ Quantum Hall State
• Density Matrix Renormalization Group Study of Incompressible Fractional Quantum Hall States
• Fractional Quantum Hall Effect in the Second Landau Level
• Microscopic Theory of the Reentrant IQHE in the First and Second Excited LLs

Cited by in corpus (10)

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• Fractional Quantum Hall Hierarchy and the Second Landau Level
• The non-Abelian Interferometer
• Limit to 2D mobility in modulation-doped GaAs quantum structures: How to achieve a mobility of 100 millions
• Intrinsic Gap of the nu=5/2 Fractional Quantum Hall State
• Spin polarization of the $\nu =5/2$ quantum Hall state
• Orbital Landau level dependence of the fractional quantum Hall effect in quasi-two dimensional electron layers: finite-thickness effects
• Thermopower as a Possible Probe of Non-Abelian Quasiparticle Statistics in Fractional Quantum Hall Liquids
• Observation of a Fractional Quantum Hall State at $\nu =1/4$ in a Wide GaAs Quantum Well
• Fractional quantum Hall state at ν=1/4 in a wide quantum well