arXiv subjects

M. A. Hidalgo

Publications and source records attributed to M. A. Hidalgo.

10 recordsLinked to original sources

arXiv2026

Phenomenological geometric ordering in fractional quantum Hall systems

The fractional quantum Hall effect (FQHE) is conventionally understood in terms of strongly correlated many-body states and emergent quasiparticles with fractional charge. Here, we propose a complementary phenomenological framework in which impurity-induced geometric correlations within a Landau level contribute to the organization and stability of fractional quantum Hall states. The model considers a two-dimensional electron gas coupled to a correlated distribution of ionized impurities located at a finite distance from the electronic layer. Impurity-induced overlap between displaced Landau orbitals generates coherent guiding-center correlations and an effective splitting of the Landau-level degeneracy into fractional sublevels. Within this framework, the resulting energy spectrum reproduces the principal odd-denominator fractional sequences through the interplay between guiding-center quantization and impurity-induced orbital coherence. An explicit expression for the correlation energy is obtained in terms of the magnetic length, impurity spacing, and impurity-layer separation, providing a direct connection between the proposed mechanism and experimentally controllable heterostructure parameters. The model naturally incorporates the integer quantum Hall regime as the limiting case of vanishing correlation-induced splitting. Within this geometric picture, effective fractional factors emerge from collective orbital coherence and correlation-modified guiding-center dynamics rather than being uniquely associated with independent fractionally charged quasiparticles. Although the model does not attempt to derive topological order, anyonic statistics, or many-body incompressibility, it suggests that impurity-induced geometry and guiding-center coherence may provide an additional contribution to the emergence, stability, and experimental visibility of fractional quantum Hall states.

cond-mat.mes-hall↗

arXiv2026

Impurity-induced geometric correlations and fractional quantization in quantum Hall systems

We propose a geometric mechanism for fractional quantum Hall states based on impurity-induced correlations within a Landau level. A correlated distribution of ionized impurities partially modifies the Landau-level degeneracy through coherent coupling between cyclotron orbits, generating fractional energy sublevels. The odd-denominator hierarchy emerges naturally from the intrinsic guiding-center quantization and the correlated cyclotron motion. The resulting spectrum reproduces the principal experimentally observed fractional sequences and predicts a strong dependence of fractional-state stability on impurity geometry and layer separation. The absence of an incompressible Hall plateau at filling factor 1/2 follows from cancellation of the geometric correlations responsible for odd-denominator states. These results suggest that impurity-induced geometry may constitute an additional organizing principle in quantum Hall systems.

cond-mat.mes-hall↗

arXiv2025

An Approach to the Quantum Hall Effect in Three- Dimensional Electron Systems

We present a theoretical framework to describe the integer quantum Hall effect (IQHE) in three-dimensional (3D) electron systems. This extends our previous single-electron approach, which was successfully applied to two-dimensional (2D) systems such as semiconductor quantum wells and graphene, where insights provided into both the IQHE and the fractional quantum Hall effect (FQHE). Starting from the graphene model, where the unconventional sequence of Hall plateaux, 2(2n+1), naturally emerges from Landau quantization, we generalize the formulation to 3D semimetals with low carrier density and high mobility, where recent experiments have reported signatures of the QHE. For 3D systems, the model accounts for strong band anisotropy by introducing an effective correction to the cyclotron frequency, and, also by considering large effective gyromagnetic factor, as observed in semimetallic materials. From the calculated density of states and carrier concentration, we derive semiclassical expressions for the diagonal and Hall conductivities. The resulting Hall conductivity exhibits quantized values in agreement with theoretical predictions and experimental observations of 3D quantum Hall states. Simulations reproduce both Hall plateaux and Shubnikov de Haas oscillations under realistic parameter sets. Our results demonstrate that the IQHE in 3D semimetals can be understood as a natural extension of the single-electron Landau quantization framework originally developed for 2D systems. This provides a unified picture of quantum magnetotransport across dimensions, highlighting the crucial role of low carrier density and high mobility. The model further suggests new avenues for analyzing thermodynamic and transport properties in 3D systems under quantum Hall conditions.

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arXiv2020

Quantum Hall effects in two-dimensional electron systems: A global approach

Up to almost the last two decades all the experimental results concerning the quantum Hall effect (QHE), i.e., the observation of plateaux at integer (IQHE) or fractional (FQHE) values of the constant h/e2, were related to quantum-wells in semiconductor heterostructures (QWs). However, more recently, a renewed interest in revisiting these phenomena has arisen thanks to the observation of entirely similar effects in graphene and topological insulators. In this paper we show an approach encompassing all these QHEs using the same theoretical frame, entailing both Hall effect plateaux and Shubnikov-de Haas (SdH) oscillations. Moreover, the model also enables the analysis of both phenomena as a function not only of the magnetic field but the gate voltage as well. More specifically, in light of the approach, the FQHE in any two-dimensional electron system (2DES) appears to be an effect of the breaking of the degeneration of every Landau level, n, as a result of the electrostatic interaction involved, and being characterized by the set of three integer numbers (n, p, q), where p and q have clear physical meanings too.

cond-mat.mes-hall↗

arXiv2016

A study of the magnetotransport properties of the graphene (III. Bilayer)

The present paper corresponds to the third work of the author related to the magnetotransport properties concerning on the graphene systems. In the first one the integer quantum Hall effect in the monolayer graphene, (MG), MGIQHE, was analysed, (Hidalgo, 2014). The subject of the second one was the understanding of the fractional quantum Hall also in the MG, (MGFQHE), (Hidalgo, 2015), basing us in our model on the fractional quantum Hall effect in semiconductor quantum systems, Hidalgo (2013). The aim of the present work is the analysis of the integer quantum Hall effect observed in bilayer graphene, (BG), BGIQHE, as a function of both, the gate voltage and the magnetic field. Our approach is a single electron approach, firstly developed for the study of the integer quantum Hall (IQHE) and Shubnikov-de Haas (SdH) effects of a two-dimensional electron gas (2DEG) in any semiconductor quantum well (QW), (Hidalgo, 1995, 1998, 2007). The extension of this model for the BG reproduces its main observed features for the IQHE and the SdH, and as a function of both, the gate voltage and the magnetic field, in particular the plateaux at the values , with n=0,1,2... Therefore, the approach integrates the quantum Hall effects (integer and fractional) observed in both, QW and graphene, in the same physical frame.

cond-mat.mes-hall↗

arXiv2015

A study of the magnetotransport properties of the graphene (II. Fractional Quantum Hall Effect)

We present an approach to the fractional quantum Hall effect observed in grapheme (GFQHE), basing us on the model developed previously for the fractional quantum Hall effect in a two-dimensional electron system embedded in a quantum well (FQHE) [Hidalgo, 2013(*)]. The main idea in the view proposed f0r the FQHE is the breaking of the symmetry of the Hamiltonian of every electron in a two-dimensional electron gas (2DEG) under the application of a magnetic field and in the presence of an electrostatic potential due to the ionized impurities. As the magnetic field increases the effect of that electrostatic potential evolves; changing in turn the spatial symmetry of the Hamiltonian: from continuous to discrete one. The model provides the odd fractional states, and corresponding plateaux, p/3, p being any integer, observed in graphene.

cond-mat.mes-hall↗

arXiv2014

A study of the magnetotransport properties of the graphene (I. Monolayer)

We present a single electron approach to analyse the magnetotransport properties of the monolayer graphene as a function of both, the gate voltage and the magnetic field; and, also, their evolution with temperature. The model proposed means the extension of our previous one developed for studying the quantum Hall and Shubnikov-de Haas effects of a two-dimensional electron system in a semiconductor quantum well. Now, the study in this framework of both phenomena in graphene involves including the presence of two bands and two degeneracy valleys, (points K and K' in the reciprocal space). Based in a single electron approximation, we show it is capable to reproduce the entire characteristics observed in the experiments for the Hall and diagonal magnetoconductivities (and the corresponding magnetoresistivities), as a function of the gate voltage and the magnetic field. In the model the observed Hall plateaux series in the monolayer graphene, determined by the expression 2(2n+1), arises in a natural way as a consequence of the particular quantization of the energy spectrum of graphene. Therefore, on the other hand the proposed approach integrates the quantum Hall effects observed in graphene and quantum wells semiconductors

cond-mat.mes-hall↗

arXiv2013

A study of the fractional quantum Hall effect: Odd and even denominator plateaux

We present a different approach to the fractional quantum Hall effect (FQHE), focusing it as a consequence of the change in the symmetry of the Hamiltonian of every electron in a two-dimensional electron gas (2DEG) under the application of a magnetic field and in the presence of an electrostatic potential due to the ionized impurities, and leading to a breaking of the degeneration of the Landau levels. As the magnetic field increases the effect of that electrostatic potential evolves, changing in turn the spatial symmetry of the Hamiltonian: from continuous to discrete one. The aim of both works is to give a different picture not only of the FQHE phenomenon, but a coherent one with the integer quantum Hall effect (IQHE) and consistent with the model already described in Hidalgo7, 8, 9. Therefore the model gives a global view of both effects, showing that they are aspects of the same phenomenon, and justifying not only the appearance of the odd denominator plateaux but also the even ones; and giving some physical reasons for the experimental fact that there are much more odd than even denominator plateaux, hardly observed

cond-mat.mes-hall↗

arXiv2013

Observable effects of Interplanetary Coronal Mass Ejections on ground level neutron monitor counting rates

In this work, non-recurrent Forbush decreases (FDs) triggered by the passage of shock-driven interplanetary coronal mass ejections (ICMEs) have been analyzed. Fifty-nine ICMEs have been studied but only the 25% of them were associated to a FD. We find that shock-driving magnetic clouds (MCs) produce deeper FDs than shock-driving ejecta. This fact can be explained regarding to the observed growing trends between decreases in neutron monitor (NM) count rate and MC/ejecta speed and its associated rigidity. MCs are faster and have higher associated rigidities than ejecta. Also the deceleration of ICMEs seems to be a cause in producing FDs as can be inferred from the decreasing trend between NM count rate and deceleration. This probably implies that the interaction between the ICME traveling from the corona to the Earth and the solar wind can play an important role to produce deeper FDs. Finally, we conclude that ejecta without flux rope topology are the less effective in unchaining FDs.

astro-ph.SR↗

arXiv2012

Spin Magnetotransport in a Two-Dimensional Electron System under quantum Hall regime and with Rashba spin-orbit effect

The article shows a simple model that computes the magnetoconduction and the integer quantum Hall effect (IQHE) in a two-dimensional electron system (2DES) where the spin is other degree of freedom in the system. The 2DES is confined in a quantum well (QW) immersed in a heterostructure, where the Rashba spin-orbit interaction is present. When an external magnetic field is applied to the system, the competition between the spin-orbit interaction and the Zeeman effect on the magnetoconduction of the 2DES is analysed. Also the model reproduces the case where two sub-bands are occupied in the QW. In this case different spin oriented 2DES concerned to each subband can be treated independently, assuming the whole system as the sum of four independient systems (two subbands plus two 2DES spin systems in each subband). The model has been tested with experimental results obtained from a 2DES formed in an InGaAs layer for one and two subbands.

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