Possible Reentrance of the Fractional Quantum Hall Effect in the Lowest Landau Level

In the framework of a recently developed model of interacting composite fermions, we calculate the energy of different solid and Laughlin-type liquid phases of spin-polarized composite fermions. The liquid phases have a lower energy than the competing solids around the electronic filling factors nu=4/11,6/17, and 4/19 and may thus be responsible for the fractional quantum Hall effect at nu=4/11. The alternation between solid and liquid phases when varying the magnetic field may lead to reentrance phenomena in analogy with the observed reentrant integral quantum Hall effect.Comment: 4 pages, 3 figures; revised version accepted for publication in Phys. Rev. Let

Second Generation of Composite Fermions and the Self-Similarity of the Fractional Quantum Hall Effect

A recently developed model of interacting composite fermions, is used to investigate different composite-fermion phases. Their interaction potential allows for the formation of both solid and new quantum-liquid phases, which are interpreted in terms of second-generation composite fermions and which may be responsible for the fractional quantum Hall states observed at unusual filling factors, such as nu=4/11. Projection of the composite-fermion dynamics to a single level, involved in the derivation of the Hamiltonian of interacting composite fermions, reveals the underlying self-similarity of the model.Comment: 4 pages, 1 figure; to appear in "Proceedings of the 16th International Conference on High Magnetic Fields in Semiconductor Physics (SemiMag-16)", only change with respect to v1: correction in authors line, no changes in manuscrip

Quantum Phases in Partially Filled Landau Levels

We compare the energies of different electron solids, such as bubble crystals with triangular and square symmetry and stripe phases, to those of correlated quantum liquids in partially filled intermediate Landau levels. Multiple transitions between these phases when varying the filling of the top-most partially filled Landau level explain the observed reentrance of the integer quantum Hall effect. The phase transitions are identified as first-order. This leads to a variety of measurable phenomena such as the phase coexistence between a Wigner crystal and a two-electron bubble phase in a Landau-level filling-factor range $4.15 < nu < 4.26$, which has recently been observed in transport measurements under micro-wave irradiation.Comment: 6 pages, 2 figures; to appear in "Proceedings of the 16th International Conference on High Magnetic Fields in Semiconductor Physics (SemiMag-16)

Precisão experimental na predição de valores genéticos de progênies de arroz.

O objetivo deste trabalho foi comparar a eficiência do método de Papadakis, na correção da variação ambiental, com os delineamentos em blocos ao acaso e látice

Potencial genético de progênies de arroz irrigado avaliado por meio do método de Papadakis.

Este trabalho foi realizado no ano agrícola de 2012/2013, com o objetivo de comparar a eficiência do método de Papadakis na correção da variação ambiental em relação ao delineamento látice.Apresentação oral - Pós-graduação

Variabilidade genética com seleção recorrente em arroz de terras altas.

O objetivo deste trabalho foi obter estimativas de parâmetros genéticos e fenotípicos entre progênies S0:2 da população CNA6 de arroz de terras altas durante quatro ciclos de seleção recorrente, visando analisar a variabilidade genética para o caráter produção de grãos (PG, em kg ha-1)

On the self-similarity in quantum Hall systems

The Hall-resistance curve of a two-dimensional electron system in the presence of a strong perpendicular magnetic field is an example of self-similarity. It reveals plateaus at low temperatures and has a fractal structure. We show that this fractal structure emerges naturally in the Hamiltonian formulation of composite fermions. After a set of transformations on the electronic model, we show that the model, which describes interacting composite fermions in a partially filled energy level, is self-similar. This mathematical property allows for the construction of a basis of higher generations of composite fermions. The collective-excitation dispersion of the recently observed 4/11 fractional-quantum-Hall state is discussed within the present formalism.Comment: 7 pages, 4 figures; version accepted for publication in Europhys. Lett., new version contains energy calculations for collective excitations of the 4/11 stat

Staircase to Higher-Order Topological Phase Transitions

We find a series of topological phase transitions of increasing order, beyond the more standard second-order phase transition in a one-dimensional topological superconductor. The jumps in the order of the transitions depend on the range of the pairing interaction, which is parametrized by an algebraic decay with exponent $\alpha$. Remarkably, in the limit $\alpha = 1$ the order of the topological transition becomes infinite. We compute the critical exponents for the series of higher-order transitions in exact form and find that they fulfill the hyperscaling relation. We also study the critical behaviour at the boundary of the system and discuss potential experimental platforms of magnetic atoms in superconductors.Comment: 5+5pages, 7 figures. Accepted as a Rapid Communicatio

Avaliação de genótipos de arroz de sequeiro nos cerrados de Rondônia - 1996/97.

Visando avaliar linhagens/cultivares de arroz de sequeiro para as condições dos cerrados de Rondônia, com elevadas produtividades, resistentes às principais doenças e com boas características de grãos, foi conduzido este ensaio no Campo Experimental da Embrapa Rondônia, no município de Vilhena.bitstream/item/79035/1/FOL-6142-0001.pd