Related papers: Filling factor dependence of the fractional quantu…
Two dimensional electron systems exhibiting the fractional quantum Hall effects are characterized by a quantized Hall conductance and a dissipationless bulk. The transport in these systems occurs only at the edges where gapless excitations…
The thermodynamic potential of an ideal nonrelativistic gas of two-dimensional electrons in crossed uniform magnetic and electric fields is constructed. For low temperatures and very weak electric fields, it is shown that the Hall…
We report the first unambiguous observation of a fractional quantum Hall state in the Landau level of a two-dimensional hole sample at the filling factor $\nu=8/3$. We identified this state by a quantized Hall resistance and an activated…
We compute energy gaps for spin-polarized fractional quantum Hall states in the lowest Landau level at filling fractions nu=1/3, 2/5,3/7 and 4/9 using exact diagonalization of systems with up to 16 particles and extrapolation to the…
The quantum Hall effect in ultra-high mobility GaAs/AlGaAs has been measured and plateaus are found at many different fractions. The resistivity is quantized as \rho =h/ie^2 where i exhibits many different values. The fractions 5/3, 8/5,…
We study the magneto-conductance of a $1.4~\mathrm{\mu m}$-wide quantum dot in the fractional quantum Hall regime. For a filling factor $\approx 2/3$ and $\gtrsim 1/3$ in the quantum dot the observed Coulomb resonances show a periodic…
Effect of interlayer tunneling in the double-layer fractional quantum Hall system at the total Landau level filling of $\nu=1/m$ ($m$: odd integer) is analyzed with the composite-fermion approach in which the flux attachment is directly…
We study the ground state of a nematic phase of the two-dimensional electron gas at filling fraction $\nu = 1/2$ using a variational wavefunction having Jastrow pair-correlations of the form $\Pi_{i < j}(z_i-z_j)^2$ and an elliptical Fermi…
New low-lying excitations are observed by inelastic light scattering at filling factors $\nu=p/(\phi p \pm 1)$ of the fractional quantum Hall regime with $\phi=4$. Coexisting with these modes throughout the range $\nu \leq 1/3$ are $\phi=2$…
We numerically study the fractional quantum Hall effect at filling factors $\nu=12/5$ and 13/5 (the particle-hole conjugate of 12/5) in high-quality two-dimensional GaAs heterostructures via exact diagonalization including finite well width…
We develop a microscopic formalism to study the fractional quantum Hall plateaus at filling factors $\nu $ away from $1/2\beta$ $\beta$ an integer. The theory is in terms of quasiparticles which carry a charge $e^{\ast}$ equal to…
We solve models of $N$ species of fermions in the lowest Landau level with $U(N)$-invariant interactions in the $N\gg 1$ limit. We find saddles of the second quantized path integral at fixed chemical potential corresponding to fractional…
It is demonstrated that a uniform magnetic field can exactly pair the two-dimensional (2D) charged particles only for some quantized magnetic intensity values. For the particle-pair consisting of two like charges the Landau level of the…
We calculate the phase diagram of the two component fractional quantum Hall effect as a function of the spin or valley Zeeman energy and the filling factor, which reveals new phase transitions and phase boundaries spanning many fractional…
In an ideal two-component two-dimensional electron system, particle-hole symmetry dictates that the fractional quantum Hall states around $\nu = 1/2$ are equivalent to those around $\nu = 3/2$. We demonstrate that composite fermions (CFs)…
Emergence of half-integer filling factor states, such as nu=5/2 and 7/2, is found in quantum dots by using numerical many-electron methods. These states have interesting similarities and differences with their counterstates found in the…
We have measured the quantum-Hall activation gaps in graphene at filling factors $\nu=2$ and $\nu=6$ for magnetic fields up to 32 T and temperatures from 4 K to 300 K. The $\nu =6$ gap can be described by thermal excitation to broadened…
We report the observation of developing fractional quantum Hall states at Landau level filling factors $\nu = 1/2$ and 1/4 in electron systems confined to wide GaAs quantum wells with significantly $asymmetric$ charge distributions. The…
We report magneto-transport measurements for the fractional quantum Hall state at filling factor $\nu=$ 5/2 as a function of applied parallel magnetic field ($B_{||}$). As $B_{||}$ is increased, the 5/2 state becomes increasingly…
Termination of the fractional quantum Hall states (FQHSs) and the emergence of Wigner crystal phases at very small Landau level filling factors ($\nu$) have been of continued interest for decades. Recently, in ultra-high-quality, dilute…