Related papers: Evidence for Skyrmions and Single Spin Flips in th…
Energy gaps have been measured for the ferromagnetic quantum Hall effect states at v=1 and 3 in GaAs/GaAlAs heterojunctions as a function of Zeeman energy, which is reduced to zero by applying hydrostatic pressures of up to 20kbar. At large…
The Pfaffian quantum Hall states, which can be viewed as involving pairing either of spin-polarized electrons or of composite fermions, are generalized by finding the exact ground states of certain Hamiltonians with k+1-body interactions,…
When a gas of electrons is confined to two dimensions, application of a strong magnetic field may lead to startling phenomena such as emergence of electron pairing. According to a theory this manifests itself as appearance of the fractional…
We construct model wavefunctions for a family of single-quasielectron states supported by the $\nu=1/3$ fractional quantum Hall (FQH) fluid. The charge $e^*$ = $e/3$ quasielectron state is identified as a composite of a charge-$2e^*$…
Using a self consistent approximation for the spin distribution of Skyrmions in the quantum Hall effect, we obtain an effective action for the Skyrmion coordinates. The energy functional is minimised for a periodic distribution of Skyrmions…
We study broken symmetry states at integer Landau level fillings in multivalley quantum Hall systems whose low energy dispersions are anisotropic. When the Fermi surface of individual pockets lacks twofold rotational symmetry, like in…
We report on an absolute measurement of the electronic spin polarization of the $\nu=1$ integer quantum Hall state. The spin polarization is extracted in the vicinity of $\nu=1$ (including at exactly $\nu=1$) via resistive NMR experiments…
It is well known that the Fractional Quantum Hall Effect (FQHE) may be effectively represented by a Chern-Simons theory. In order to incorporate QH Skyrmions, we couple this theory to the topological spin current, and include the Hopf term.…
At half filling of the fourfold degenerate Landau levels |n| \geq 1 in graphene, the ground states are spin polarized quantum Hall states that support spin skyrmion excitations for |n| =1,2,3. Working in the Hartree-Fock approximation, we…
The flow of electric current through a two-dimensional material in a magnetic field gives rise to the family of Hall effects. The quantum versions of these effects accommodate robust electronic edge channels and fractional charges.…
We derive the low-energy theory of semi-quantized quantum Hall states, a recently observed class of gapless bilayer fractional quantum Hall states. Our theory shows these states to feature gapless quasiparticles of fractional charge coupled…
Analyzing the effective conformal field theory for the parafermionic Hall states, corresponding to filling fractions nu_k=2+k/(kM+2), k=2,3,..., M odd, we show that the even k plateaux are expected to be more stable than their odd k…
The Hartree-Fock paradigm of bilayer quantum Hall states with finite tunneling at filling factor $\nu$=1 has full pseudospin ferromagnetic order with all the electrons in the lowest symmetric Landau level. Inelastic light scattering…
We fabricate high-mobility p-type few-layer WSe2 field-effect transistors and surprisingly observe a series of quantum Hall (QH) states following an unconventional sequence predominated by odd-integer states under a moderate strength…
The quantum Hall liquid is a novel state of matter with profound emergent properties such as fractional charge and statistics. Existence of the quantum Hall effect requires breaking of the time reversal symmetry caused by an external…
Two-dimensional semiconductor quantum dots are studied in the the filling-factor range 2<v<3. We find both theoretical and experimental evidence of a collective many-body phenomenon, where a fraction of the trapped electrons form an…
The chiral two-dimensional electron gas in Landau levels $\left\vert N\right\vert >0$ of a Bernal-stacked graphene bilayer has a valley-pseudospin Ising quantum Hall ferromagnetic behavior at odd filling factors $\nu _{N}=1,3$ of these…
Excitation modes in the range $2/5 \geq \nu \geq 1/3$ of the fractional quantum Hall regime are observed by resonant inelastic light scattering. Spectra of spin reversed excitations suggest a structure of lowest spin-split Landau levels of…
It is shown that the ground-state and the lowest excited-states of two-dimensional electron system (2DES), with ion jellium background, correspond to partial crystal-like (with the period $L_{x}^{\square}=\sqrt{2 m \pi} \ell_{0}$)…
The average electron spin-polarization $\cal P$ of two-dimensional electron gas confined in $\rm GaAs/GaAlAs$ multiple quantum-wells was measured by nuclear magnetic resonance (NMR) near the fractional quantum Hall state with filling factor…