Resonant scattering of Dice quasiparticles on oscillating quantum dots

Filusch, Alexander; Wurl, Christian; Fehske, Holger

doi:10.1140/epjb/e2020-100600-2

Cited by 5 publications

(3 citation statements)

References 44 publications

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“…There are also several suggestions for an optical α-T 3 lattice that would allow a tuning of α by dephasing one pair of the three counter-propagating laser beams [28,30]. Under external electromagnetic fields, the flat band and α-dependent Berry phase have striking consequences on the Landau level quantization [28,31], the quantum Hall effect [32,33], Klein tunneling [34][35][36][37] and Weiss oscillations [38]. While the flat band has zero group ve-locity and therefore zero conductivity, it is predicted to play an important role for the transport by its nontrivial topology [29,44], the coupling to propagating bands [39][40][41], or interaction effects [42][43][44][45].…”

Section: Introductionmentioning

confidence: 99%

Tunable valley filtering in dynamically strained $α$-$\mathcal{T}_3$ lattices

Filusch¹,

Fehske²

2022

Preprint

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Mechanical deformations in α-T3 lattices induce local pseudomagnetic fields of opposite directionality for different valleys. When this strain is equipped with a dynamical drive, it generates a complementary valley-asymmetric pseudoelectric field which is expected to accelerate electrons. We propose that by combining these effects by a time-dependent nonuniform strain, tunable valley filtering devices can be engineered that extend beyond the static capabilities. We demonstrate this by implementing an oscillating Gaussian bump centered in a four-terminal Hall bar α-T3 setup and calculating the induced pseudoelectromagnetic fields analytically. Within a recursive Floquet Green-function scheme, we determine the time-averaged transmission and valley polarization, as well as the spatial distributions of the local density of states and current density. As a result of the periodic drive, we detect novel energy regimes with highly valley-polarized transmission, depending on α. Analyzing the spatial profiles of the time-averaged local density of states and current density we can relate these regimes to the pseudoelectromagnetic fields in the setup. By means of the driving frequency, we can manipulate the valley-polarized states, which might be advantageous for future device applications.

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Section: Introductionmentioning

confidence: 99%

Tunable valley filtering in dynamically strained $α$-$\mathcal{T}_3$ lattices

Filusch¹,

Fehske²

2022

Preprint

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“…One of the options is nanoscale top gates that modify the electronic structure in a restricted area [10]. This allows to imprint junctions and barriers relatively easy, and therefore opens new possibilities to study fascinating phenomena such as Klein tunnelling [11,12], Zitterbewegung [13,14], particle confinement [15,16], Veselago lensing [17], Mie scattering analogues [18][19][20][21][22] and resonant scattering [23,24]. Clearly the energy of the charge-carrier states can be manipulated by (perpendicular) magnetic fields as well.…”

Section: Introductionmentioning

confidence: 99%

Electronic properties of α − 𝒯3 quantum dots in magnetic fields

Filusch

Fehske

2020

Eur. Phys. J. B

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We address the electronic properties of quantum dots in the two-dimensional α − 𝒯3 lattice when subjected to a perpendicular magnetic field. Implementing an infinite mass boundary condition, we first solve the eigenvalue problem for an isolated quantum dot in the low-energy, long-wavelength approximation where the system is described by an effective Dirac-like Hamiltonian that interpolates between the graphene (pseudospin 1/2) and Dice (pseudospin 1) limits. Results are compared to a full numerical (finite-mass) tight-binding lattice calculation. In a second step we analyse charge transport through a contacted α − 𝒯3 quantum dot in a magnetic field by calculating the local density of states and the conductance within the kernel polynomial and Landauer-Büttiker approaches. Thereby the influence of a disordered environment is discussed as well. Graphical abstract

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“…One of the options are nanoscale top gates that modify the electronic structure in a restricted area [10]. This allows to imprint junctions and barriers relatively easy, and therefore opens new possibilities to study fascinating phenomena such as Klein tunnelling [11,12], Zitterbewegung [13,14], particle confinement [15,16], Veselago lensing [17], Mie scattering analogues [18,19,20,21,22] and resonant scattering [23,24]. Clearly the energy of the charge-carrier states can be manipulated by (perpendicular) magnetic fields as well.…”

Section: Introductionmentioning

confidence: 99%

Electronic Properties of $α-\mathcal{T}_3$ Quantum Dots in Magnetic Fields

Filusch,

Fehske

2020

Preprint

Self Cite

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We address the electronic properties of quantum dots in the two-dimensional α−T3 lattice when subjected to a perpendicular magnetic field. Implementing an infinite mass boundary condition, we first solve the eigenvalue problem for an isolated quantum dot in the low-energy, long-wavelength approximation where the system is described by an effective Dirac-like Hamiltonian that interpolates between the graphene (pseudospin 1/2) and Dice (pseudospin 1) limits. Results are compared to a full numerical (finite-mass) tight-binding lattice calculation. In a second step we analyse charge transport through a contacted α − T3 quantum dot in a magnetic field by calculating the local density of states and the conductance within the kernel polynomial and Landauer-Büttiker approaches. Thereby the influence of a disordered environment is discussed as well.

show abstract

Resonant scattering of Dice quasiparticles on oscillating quantum dots

Cited by 5 publications

References 44 publications

Tunable valley filtering in dynamically strained $α$-$\mathcal{T}_3$ lattices

Tunable valley filtering in dynamically strained $α$-$\mathcal{T}_3$ lattices

Electronic properties of α − 𝒯3 quantum dots in magnetic fields

Electronic Properties of $α-\mathcal{T}_3$ Quantum Dots in Magnetic Fields

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