Composite fermions in a wide quantum well in the vicinity of the filling factor 1/2

Abstract

Using acoustic method we study dependences of transverse AC conductance, $\sigma (\omega )$, on magnetic field, temperature and the amplitude of AC electric field in a wide (75 nm) quantum well (QW) structure focusing on the vicinity of the filling factor $\nu =1/2$. Measurements are performed in the frequency domain 30-307 MHz and in the temperature domain 20-500 mK. Usually, in wide QW structures closely to $\nu =1/2$ the fractional quantum Hall effect (FQHE) regime is realized at some parameters of the sample. However, in our structure, at $\nu =1/2$ it is a compressible state corresponding to gas of composite fermions which is observed. This is confirmed by apparent frequency independence and weakly decreasing temperature dependence of $\mathrm{Re}\sigma (\omega )$. Comparing the dependences of this quantity on temperature and power of the acoustic wave we conclude that the observed nonlinear behavior of the conductance is compatible with heating of the composite fermions by the acoustic wave. For comparison, we also study the vicinity of $\nu =3/2$ where the FQHE regime is clearly observed.

6 pages, 6 figures

References in corpus (3)

• Non-Abelian Anyons and Topological Quantum Computation
• Quantum Hall Phase Diagram of Half-filled Bilayers in the Lowest and the Second Orbital Landau Levels: Abelian versus Non-Abelian Incompressible Fractional Quantum Hall States
• $\nu =1/2$ Fractional Quantum Hall Effect in Tilted Magnetic Fields

Cited by in corpus (4)

• Origin of the $\nu =1/2$ fractional quantum Hall effect in wide quantum wells
• Dispersion of neutral collective modes in partonic fractional quantum Hall states and its applications to paired states of composite fermions
• Interplay of superconducting, metallic, and crystalline states of composite fermions at $\nu =1/6$ in wide quantum wells
• Repulsive-Interaction-Driven Topological Superconductivity in a Landau Level Coupled to an $s$-Wave Superconductor