Resonant tunneling in a quantum waveguide: Effect of a finite-size attractive impurity

Kim, Chang Sub; Satanin, A. M.; Joe, Yong S.; Cosby, R. M.

doi:10.1103/physrevb.60.10962

Cited by 154 publications

(128 citation statements)

References 29 publications

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“…These single-resonance parametric BICs can also exist in non-periodic structures, as shown theoretically in acoustic and water waveguides with an obstacle [143][144][145][146][147][148] , in quantum waveguides with impurities [149][150][151] or bends 95,152,153 , for mechanically coupled beads 29,30 and mechanical resonators 154 , and in optics for a low-index waveguide on a high-index membrane 155 .…”

Section: Single Resonancementioning

confidence: 99%

Bound states in the continuum

et al. 2016

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Bound states in the continuum are waves that, defying conventional wisdom, remain localized even though they coexist with a continuous spectrum of radiating waves that can carry energy away. Their existence was first proposed in quantum mechanics and, being a general wave phenomenon, later identified in electromagnetic, acoustic, and water waves. They have been studied in a wide variety of material systems such as photonic crystals, optical waveguides and fibers, piezoelectric materials, quantum dots, graphene, and topological insulators. This Review describes recent developments in this field with an emphasis on the physical mechanisms that lead to these unusual states across the seemingly very different platforms. We discuss recent experimental realizations, existing applications, and directions for future work.

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Section: Single Resonancementioning

confidence: 99%

Bound states in the continuum

et al. 2016

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“…The change of the sign of κ interchanges priority of B m=±1 that in turn changes the direction of spiralling. The next unique property of the BSC is related to the Fano resonance collapse [78,97] that reflects in resonant features of the cross sections of the array in the vicinity of the BSC frequency. Similar to the BSCs with β = 0 and m = 0 which were presented in Ref.…”

Section: Propagating Bloch Bscs With Orbital Angular Momentummentioning

confidence: 99%

Light Trapping above the Light Cone in One-Dimensional Arrays of Dielectric Spheres

2017

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Abstract:We demonstrate bound states in the radiation continuum (BSC) in a linear periodic array of dielectric spheres in air above the light cone. We classify the BSCs by orbital angular momentum m = 0, ±1, ±2 according to the rotational symmetry of the array, Bloch wave vector β directed along the array according to the translational symmetry, and polarization. The most simple symmetry protected BSCs have m = 0, β = 0 and occur in a wide range of the radius of the spheres and dielectric constant. More sophisticated BSCs with m = 0, β = 0 exist only for a selected radius of spheres at fixed dielectric constant. We also find robust Bloch BSCs with β = 0, m = 0. All BSCs reside within the first but below the other diffraction continua. We show that the BSCs can be easily detected by bright features in scattering of different plane waves by the array as dependent on type of the BSC. The symmetry protected TE/TM BSCs can be traced by collapsing Fano resonance in cross-sections of normally incident TE/TM plane waves. When plane wave with circular polarization with frequency tuned to the bound states with OAM illuminates the array the spin angular momentum of the incident wave transfers into the orbital angular momentum of the BSC. This, in turn, gives rise to giant vortical power currents rotating around the array. Incident wave with linear polarization with frequency tuned to the Bloch bound state in the continuum induces giant laminar power currents. At last, the plane wave with linear polarization incident under tilt relative to the axis of array excites Poynting currents spiralling around the array. It is demonstrated numerically that quasi-bound leaky modes of the array can propagate both stationary waves and light pulses to a distance of 60 wavelengths at the frequencies close to the bound states in the radiation continuum. A semi-analytical estimate for decay rates of the guided waves is found to match the numerical data to a good accuracy.

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“…They are typical of quantum-confined waveguides and result from the interference of the carrier wave function with the quasi-bound states of the higherlying subbands. [41][42][43] The number, position and width of these Fano resonances depends on the position of the impurity in the SiNW. Although they are mostly washed-out by thermal broadening at room temperature, the Fano resonances have subtle effects on the mobility, as discussed below.…”

Section: Case Study: 2 Nm Thick Hfo 2 Gate Oxidementioning

confidence: 99%

Charged impurity scattering and mobility in gated silicon nanowires

et al. 2010

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We study the effects of charged impurity scattering on the electronic transport properties of 110 -oriented Si nanowires in a gate-all-around geometry, where the impurity potential is screened by the gate, gate oxide and conduction band electrons. The electronic structure of the doped nanowires is calculated with a tight-binding method and the transport properties with a LandauerBüttiker Green functions approach and the linearized Boltzmann transport equation (LBTE) in the first Born approximation. Based on our numerical results we argue that: (1) There are large differences between Phosphorous-and Boron-doped systems, acceptors behaving as tunnel barriers for the electrons, while donors give rise to Fano resonances in the transmission. (2) As a consequence, the mobility is much larger in P-than in B-doped nanowires at low carrier density, but can be larger in B-doped nanowires at high carrier density. (3) The resistance of a single impurity is strongly dependent on its radial position in the nanowire, especially for acceptors. (4) As a result of subband structure and screening effects, the impurity-limited mobility can be larger in thin nanowires embedded in HfO 2 than in bulk Si. Acceptors might, however, strongly hinder the flow of electrons in thin nanowires embedded in SiO 2 . (5) The perturbative LBTE largely fails to predict the correct mobilities in quantum-confined nanowires.

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Resonant tunneling in a quantum waveguide: Effect of a finite-size attractive impurity

Cited by 154 publications

References 29 publications

Bound states in the continuum

Bound states in the continuum

Light Trapping above the Light Cone in One-Dimensional Arrays of Dielectric Spheres

Charged impurity scattering and mobility in gated silicon nanowires

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