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“Bound vortex states and exotic lattices in multicomponent Bose-Einstein condensates : the role of vortex-vortex interaction”. Dantas DS, Lima ARP, Chaves A, Almeida CAS, Farias GA, Milošević, MV, Physical review : A : atomic, molecular and optical physics 91, 023630 (2015). http://doi.org/10.1103/PhysRevA.91.023630
Abstract: We numerically study the vortex-vortex interaction in multicomponent homogeneous Bose-Einstein condensates within the realm of the Gross-Pitaevskii theory. We provide strong evidence that pairwise vortex interaction captures the underlying mechanisms which determine the geometric configuration of the vortices, such as different lattices in many-vortex states, as well as the bound vortex states with two (dimer) or three (trimer) vortices. Specifically, we discuss and apply our theoretical approach to investigate intra- and intercomponent vortex-vortex interactions in two- and three-component Bose-Einstein condensates, thereby shedding light on the formation of the exotic vortex configurations. These results correlate with current experimental efforts in multicomponent Bose-Einstein condensates and the understanding of the role of vortex interactions in multiband superconductors.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.925
Times cited: 12
DOI: 10.1103/PhysRevA.91.023630
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“Confinement of two-dimensional excitons in a non-homogeneous magnetic field”. Freire JAK, Matulis A, Peeters FM, Freire VN, Farias GA, Physical review : B : condensed matter and materials physics 61, 2895 (2000). http://doi.org/10.1103/PhysRevB.61.2895
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 22
DOI: 10.1103/PhysRevB.61.2895
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“Cyclotron resonance of trilayer graphene”. Sena SHR, Pereira JM, Farias GA, Peeters FM, Physical review : B : condensed matter and materials physics 86, 085412 (2012). http://doi.org/10.1103/PhysRevB.86.085412
Abstract: The cyclotron resonance energies, the corresponding oscillator strengths, and the cyclotron absorption spectrum for trilayer graphene are calculated for both ABA and ABC stacking. A gate potential across the stacked layers leads to (1) a reduction of the transition energies, (2) a lifting of the degeneracy of the zero Landau level, and (3) the removal of the electron-hole symmetry.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 7
DOI: 10.1103/PhysRevB.86.085412
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“Electron mobility in Si δ-doped GaAs with spatial correlations in the distribution of charged impurities”. Shi JM, Koenraad PM, van de Stadt AFW, Peeters FM, Farias GA, Devreese JT, Wolter JH, Wilamowski Z, Physical review : B : condensed matter and materials physics 55, 13093 (1997)
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 3.836
Times cited: 17
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“Electronic states above a helium film suspended on a ring-shaped substrate”. Ramos ACA, Chaves A, Farias GA, Peeters FM, Physical review : B : condensed matter and materials physics 77, 045415 (2008). http://doi.org/10.1103/PhysRevB.77.045415
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 4
DOI: 10.1103/PhysRevB.77.045415
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“Fine structure of excitons in a quantum well in the presence of a non-homogeneous magnetic field”. Freire JAK, Matulis A, Peeters FM, Freire VN, Farias GA, Physical review : B : condensed matter and materials physics 62, 7316 (2000). http://doi.org/10.1103/PhysRevB.62.7316
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 14
DOI: 10.1103/PhysRevB.62.7316
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“Graphene ribbons with a line of impurities: oOpening of a gap”. Costa Filho RN, Farias GA, Peeters FM, Physical review : B : condensed matter and materials physics 76, 193409 (2007). http://doi.org/10.1103/PhysRevB.76.193409
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 49
DOI: 10.1103/PhysRevB.76.193409
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“Hysteresis and reentrant melting of a self-organized system of classical particles confined in a parabolic trap”. Munarin FF, Nelissen K, Ferreira WP, Farias GA, Peeters FM, Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics 77, 031608 (2008). http://doi.org/10.1103/PhysRevE.77.031608
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 11
DOI: 10.1103/PhysRevE.77.031608
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“Landau levels in graphene bilayer quantum dots”. Pereira JM, Peeters FM, Vasilopoulos P, Costa Filho RN, Farias GA, Physical review : B : solid state 79, 195403 (2009). http://doi.org/10.1103/PhysRevB.79.195403
Abstract: We investigate localized electron and hole states in parabolic quantum dots of biased graphene bilayers in the presence of a perpendicular magnetic field. These quantum dots can be created by means of nanostructured gates or by position-dependent doping, which can create a gap in the otherwise gapless dispersion of a graphene bilayer. Numerical results show the energy levels of confined electrons and holes as a function of the dot parameters and the magnetic field. Remarkable crossings of energy levels are found.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 29
DOI: 10.1103/PhysRevB.79.195403
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“Molecular states of two vertically coupled systems of classical charged particles confined by a Coulomb potential”. Munarin FF, Ferreira WP, Farias GA, Peeters FM, Physical review : B : condensed matter and materials physics 76, 035336 (2007). http://doi.org/10.1103/PhysRevB.76.035336
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 3
DOI: 10.1103/PhysRevB.76.035336
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“Nonlinear screening in large two-dimensional Coulomb clusters”. Kong M, Vagov A, Partoens B, Peeters FM, Ferreira WP, Farias GA, Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics 70, 051807 (2004). http://doi.org/10.1103/PhysRevE.70.051807
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 4
DOI: 10.1103/PhysRevE.70.051807
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“Normal mode spectra of two-dimensional classical atoms confined by a Coulomb potential”. Ferreira WP, Peeters FM, Farias GA, Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics 68, 066405 (2003). http://doi.org/10.1103/PhysRevE.68.066405
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 9
DOI: 10.1103/PhysRevE.68.066405
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“Polaron effect on D- centers in weakly polar semiconductors”. Shi JM, Peeters FM, Farias GA, Freire JAK, Hai GQ, Devreese JT, Bednarek S, Adamowski J, Physical review : B : condensed matter and materials physics 57, 3900 (1998). http://doi.org/10.1103/PhysRevB.57.3900
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 3.836
Times cited: 28
DOI: 10.1103/PhysRevB.57.3900
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“Polaron effects in electron channels on a helium film”. Farias GA, Costa Filho RN, Peeters FM, Studart N, Physical review : B : condensed matter and materials physics 64, 104301 (2001). http://doi.org/10.1103/PhysRevB.64.104301
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 2
DOI: 10.1103/PhysRevB.64.104301
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“Polaron impurity states on a liquid helium film”. Farias GA, Peeters FM, Physical review : B : condensed matter and materials physics 55, 3763 (1997)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 8
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“Structural and dynamical properties of a quasi-one-dimensional classical binary system”. Ferreira WP, Carvalho JCN, Oliveira PWS, Farias GA, Peeters FM, Physical review : B : condensed matter and materials physics 77, 014112 (2008). http://doi.org/10.1103/PhysRevB.77.014112
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 20
DOI: 10.1103/PhysRevB.77.014112
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“Structural phase transitions and unusual melting behavior in a classical two-dimensional Coulomb bound cluster”. Ferreira WP, Partoens B, Peeters FM, Farias GA, Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics 71, 021501 (2005). http://doi.org/10.1103/PhysRevE.71.021501
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 8
DOI: 10.1103/PhysRevE.71.021501
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“Wave packet dynamics in semiconductor quantum rings of finite width”. Chaves A, Farias GA, Peeters FM, Szafran B, Physical review : B : solid state 80, 125331 (2009). http://doi.org/10.1103/PhysRevB.80.125331
Abstract: The time evolution of a wave packet injected into a semiconductor quantum ring is investigated in order to obtain the transmission and reflection probabilities. Within the effective-mass approximation, the time-dependent Schrödinger equation is solved for a system with nonzero width of the ring and leads and finite potential-barrier heights, where we include smooth lead-ring connections. In the absence of a magnetic field, an analysis of the projection of the wave function over the different subband states shows that when the injected wave packet is within a single subband, the junction can scatter this wave packet into different subbands but remarkably at the second junction the wave packet is scattered back into the subband state of the incoming wave packet. If a magnetic field is applied perpendicularly to the ring plane, transmission and reflection probabilities exhibit Aharonov-Bohm (AB) oscillations and the outgoing electrons may end up in different subband states from those of the incoming electrons. Localized impurities, placed in the ring arms, influence the AB oscillation period and amplitude. For a single impurity or potential barrier of sufficiently strong strength, the period of the AB oscillations is halved while for two impurities localized in diametrically opposite points of the ring, the original AB period is recovered. A theoretical investigation of the confined states and time evolution of wave packets in T wires is also made, where a comparison between this system and the lead-ring junction is drawn.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 40
DOI: 10.1103/PhysRevB.80.125331
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“Energy levels of bilayer graphene quantum dots”. da Costa DR, Zarenia M, Chaves A, Farias GA, Peeters FM, Physical review : B : condensed matter and materials physics 92, 115437 (2015). http://doi.org/10.1103/PhysRevB.92.115437
Abstract: Within a tight binding approach we investigate the energy levels of hexagonal and triangular bilayer graphene (BLG) quantum dots (QDs) with zigzag and armchair edges. We study AA- and AB-(Bernal) stacked BLG QDs and obtain the energy levels in both the absence and the presence of a perpendicular electric field (i.e., biased BLG QDs). Our results show that the size dependence of the energy levels is different from that of monolayer graphene QDs. The energy spectrum of AB-stacked BLG QDs with zigzag edges exhibits edge states which spread out into the opened energy gap in the presence of a perpendicular electric field. We found that the behavior of these edges states is different for the hexagonal and triangular geometries. In the case of AA-stacked BLG QDs, the electron and hole energy levels cross each other in both cases of armchair and zigzag edges as the dot size or the applied bias increases.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 21
DOI: 10.1103/PhysRevB.92.115437
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“Conductance maps of quantum rings due to a local potential perturbation”. Petrovic MD, Peeters FM, Chaves A, Farias GA, Journal of physics : condensed matter 25, 495301 (2013). http://doi.org/10.1088/0953-8984/25/49/495301
Abstract: We performed a numerical simulation of the dynamics of a Gaussian shaped wavepacket inside a small sized quantum ring, smoothly connected to two leads and exposed to a perturbing potential of a biased atomic force microscope tip. Using the Landauer formalism, we calculated conductance maps of this system in the case of single and two subband transport. We explain the main features in the conductance maps as due to the AFM tip influence on the wavepacket phase and amplitude. In the presence of an external magnetic field, the tip modifies the phi(0) periodic Aharonov-Bohm oscillation pattern into a phi(0)/2 periodic Al'tshuler-Aronov-Spivak oscillation pattern. Our results in the case of multiband transport suggest tip selectivity to higher subbands, making them more observable in the total
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 12
DOI: 10.1088/0953-8984/25/49/495301
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“The electronic properties of graphene and graphene ribbons under simple shear strain”. Sena SHR, Pereira JM, Farias GA, Peeters FM, Costa Filho RN, Journal of physics : condensed matter 24, 375301 (2012). http://doi.org/10.1088/0953-8984/24/37/375301
Abstract: A tight-binding model is used to study the energy band of graphene and graphene ribbon under simple shear strain. The ribbon consists of lines of carbon atoms in an armchair or zigzag orientation where a simple shear strain is applied in the x-direction keeping the atomic distances in the y-direction unchanged. Such modification in the lattice gives an energy band that differs in several aspects from the one without any shear and with pure shear. The changes in the spectrum depend on the line displacement of the ribbon, and also on the modified hopping parameter. It is also shown that this simple shear strain tunes the electronic properties of both graphene and graphene ribbon, opening and closing energy gaps for different displacements of the system. The modified density of states is also shown.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 15
DOI: 10.1088/0953-8984/24/37/375301
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“Exciton trapping in magnetic wire structures”. Freire JAK, Peeters FM, Freire VN, Farias GA, Journal of physics : condensed matter 13, 3283 (2001). http://doi.org/10.1088/0953-8984/13/14/305
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 3
DOI: 10.1088/0953-8984/13/14/305
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“Klein tunneling in single and multiple barriers in graphene”. Pereira JM, Peeters FM, Chaves A, Farias GA, Semiconductor science and technology 25, 033002 (2010). http://doi.org/10.1088/0268-1242/25/3/033002
Abstract: We review the transmission properties of carriers interacting with potential barriers in graphene. The tunneling of electrons and holes in quantum structures in graphene is found to display features that are in marked contrast with those of other systems. In particular, the interaction between the carriers with electrostatic potential barriers can be related to the propagation of electromagnetic waves in media with negative refraction indices, also known as metamaterials. This behavior becomes evident as one calculates the time evolution of wavepackets propagating across the barrier interface. In addition, we discuss the effect of trigonal warping on the tunneling through potential barriers.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.305
Times cited: 83
DOI: 10.1088/0268-1242/25/3/033002
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“Melting of a two-dimensional binary cluster of charged particles confined in a parabolic trap”. Ferreira WP, Munarin FF, Farias GA, Peeters FM;, Journal of physics : condensed matter 18, 9385 (2006). http://doi.org/10.1088/0953-8984/18/41/006
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 12
DOI: 10.1088/0953-8984/18/41/006
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“A two-component mixture of charged particles confined in a channel: melting”. Ferreira WP, Farias GA, Peeters FM, Journal of physics : condensed matter 22, 11 (2010). http://doi.org/10.1088/0953-8984/22/28/285103
Abstract: The melting of a binary system of charged particles confined in a quasi-one-dimensional parabolic channel is studied through Monte Carlo simulations. At zero temperature the particles are ordered in parallel chains. The melting is anisotropic and different melting temperatures are obtained according to the spatial direction, and the different kinds of particles present in the system. Melting is very different for the single-, two- and four-chain configurations. A temperature induced structural phase transition is found between two different four-chain ordered states which is absent in the mono-disperse system. In the mixed regime, where the two kinds of particles are only slightly different, melting is almost isotropic and a thermally induced homogeneous distribution of the distinct kinds of charges is observed.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 10
DOI: 10.1088/0953-8984/22/28/285103
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“Valley polarization due to trigonal warping on tunneling electrons in graphene”. Pereira JM, Peeters FM, Costa Filho RN, Farias GA, Journal of physics : condensed matter 21, 045301 (2009). http://doi.org/10.1088/0953-8984/21/4/045301
Abstract: The effect of trigonal warping on the transmission of electrons tunneling through potential barriers in graphene is investigated. We present calculations of the transmission coefficient for single and double barriers as a function of energy, incidence angle and barrier heights. The results show remarkable valley-dependent directional effects for barriers oriented parallel to the armchair or parallel to the zigzag direction. These results indicate that electrostatic gates can be used as valley filters in graphene-based devices.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 78
DOI: 10.1088/0953-8984/21/4/045301
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“Wavepacket scattering of Dirac and Schrödinger particles on potential and magnetic barriers”. Rakhimov KY, Chaves A, Farias GA, Peeters FM, Journal of physics : condensed matter 23, 275801 (2011). http://doi.org/10.1088/0953-8984/23/27/275801
Abstract: We investigate the dynamics of a charged particle moving in a graphene layer and in a two-dimensional electron gas, where it obeys the Dirac and the Schrödinger equations, respectively. The charge carriers are described as Gaussian wavepackets. The dynamics of the wavepackets is studied numerically by solving both quantum-mechanical and relativistic equations of motion. The scattering of such wavepackets by step-like magnetic and potential barriers is analysed for different values of wavepacket energy and width. We find: (1) that the average position of the wavepacket does not coincide with the classical trajectory, and (2) that, for slanted incidence, the path of the centre of mass of the wavepacket does not have to penetrate the barrier during the scattering process. Trembling motion of the charged particle in graphene is observed in the absence of an external magnetic field and can be enhanced by a substrate-induced mass term.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 32
DOI: 10.1088/0953-8984/23/27/275801
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“Low-dimensional confining structures on the surface of helium films suspended on designed cavities”. Dantas DS, Chaves A, Farias GA, Ramos ACA, Peeters FM, Journal of low temperature physics 173, 207 (2013). http://doi.org/10.1007/s10909-013-0895-5
Abstract: We investigate the formation of quantum confined structures on the surface of a liquid helium film suspended on a nanostructured substrate. We show theoretically that, by nanostructuring the substrate, it is possible to change the geometry of the liquid helium surface, opening the possibility of designing and controlling the formation of valleys with different shapes. By applying an external electric field perpendicular to the substrate plane, surface electrons can be trapped into these valleys, as in a quantum dot. We investigate how the external parameters, such as the electric field strength and the height of the liquid helium bath, can be tuned to control the energy spectrum of the trapped surface electrons.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.3
Times cited: 1
DOI: 10.1007/s10909-013-0895-5
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“Unusual quantum confined Stark effect and Aharonov-Bohm oscillations in semiconductor quantum rings with anisotropic effective masses”. de Sousa GO, da Costa DR, Chaves A, Farias GA, Peeters FM, Physical review B 95, 205414 (2017). http://doi.org/10.1103/PHYSREVB.95.205414
Abstract: The effects of external electric and magnetic fields on the energy spectrum of quantum rings made out of a bidimensional semiconductor material with anisotropic band structures are investigated within the effective-mass model. The interplay between the effective-mass anisotropy and the radial confinement leads to wave functions that are strongly localized at two diametrically opposite regions where the kinetic energy is lowest due to the highest effective mass. We show that this quantum phenomenon has clear consequences on the behavior of the energy states in the presence of applied in-plane electric fields and out-of-plane magnetic fields. In the former, the quantum confined Stark effect is observed with either linear or quadratic shifts, depending on the direction of the applied field. As for the latter, the usual Aharonov-Bohm oscillations are not observed for a circularly symmetric confining potential, however they can be reinstated if an elliptic ring with an appropriate aspect ratio is chosen.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 19
DOI: 10.1103/PHYSREVB.95.205414
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“All-strain based valley filter in graphene nanoribbons using snake states”. Cavalcante LS, Chaves A, da Costa DR, Farias GA, Peeters FM, Physical review B 94, 075432 (2016). http://doi.org/10.1103/PHYSREVB.94.075432
Abstract: A pseudomagnetic field kink can be realized along a graphene nanoribbon using strain engineering. Electron transport along this kink is governed by snake states that are characterized by a single propagation direction. Those pseudomagnetic fields point towards opposite directions in the K and K' valleys, leading to valley polarized snake states. In a graphene nanoribbon with armchair edges this effect results in a valley filter that is based only on strain engineering. We discuss how to maximize this valley filtering by adjusting the parameters that define the stress distribution along the graphene ribbon.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 29
DOI: 10.1103/PHYSREVB.94.075432
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