Flat-band exciton in two-dimensional Kagomé quantum wire systems

We propose a novel mechanism of flat band formation based on the relative biasing of only one sublattice against other sublattices in a honeycomb lattice bilayer. The mechanism allows modification of the band dispersion from parabolic to “Mexican hat”–like through the formation of a flattened band. The mechanism is well applicable for bilayer graphene—both doped and undoped. By angle-resolved photoemission from bilayer graphene on SiC, we demonstrate the possibility of realizing this extremely flattened band (< 2-meV dispersion), which extends two-dimensionally in a k-space area around the K¯ point and results in a disk-like constant energy cut. We argue that our two-dimensional flat band model and the experimental results have the potential to contribute to achieving superconductivity of graphene- or graphite-based systems at elevated temperatures.

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Self-consistent treatment of v-groove quantum wire band structure in no parabolic approximation

Serbian Journal of Electrical Engineering ◽

10.2298/sjee0403069c ◽

2004 ◽

Vol 1 (3) ◽

pp. 69-77 ◽

Cited By ~ 10

Author(s):

Jasna Crnjanski ◽

Dejan Gvozdic

Keyword(s):

Band Structure ◽

Quantum Wire ◽

The Self ◽

Flat Band ◽

Band Model ◽

Parabolic Approximation ◽

Self Consistent ◽

Band Absorption ◽

Consistent Treatment ◽

Self Consistency

The self-consistent no parabolic calculation of a V-groove-quantum-wire (VQWR) band structure is presented. A comparison with the parabolic flat-band model of VQWR shows that both, the self-consistency and the nonparabolicity shift sub band edges, in some cases even in the opposite directions. These shifts indicate that for an accurate description of inter sub band absorption, both effects have to be taken into the account.

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Using a Tunable Quantum Wire To Measure the Large out-of-Plane Spin Splitting of Quasi Two-Dimensional Holes in a GaAs Nanostructure

Nano Letters ◽

10.1021/nl303596s ◽

2012 ◽

Vol 13 (1) ◽

pp. 148-152 ◽

Cited By ~ 21

Author(s):

A. Srinivasan ◽

L. A. Yeoh ◽

O. Klochan ◽

T. P. Martin ◽

J. C. H. Chen ◽

...

Keyword(s):

Quantum Wire ◽

Spin Splitting ◽

Two Dimensional ◽

Out Of Plane

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Two-Step Evolution of the Quasiparticle Band with Doping in the Two-Dimensional t-t′-t″-J Model

International Journal of Modern Physics B ◽

10.1142/s0217979298001770 ◽

1998 ◽

Vol 12 (29n31) ◽

pp. 2914-2919

Author(s):

Chang-De Gong ◽

Wei-Guo Yin ◽

P. W. Leung

Keyword(s):

Theoretical Analysis ◽

Excellent Agreement ◽

Exact Diagonalization ◽

Flat Band ◽

Two Dimensional ◽

Doping Dependence ◽

Flat Region ◽

Half Filling ◽

Quasiparticle Band

We study the doping dependence of photoemission spectra for the t-t′-t″-J model by using the exact diagonalization technique and present a consistent theoretical analysis. Both calculations show that upon doping the enhancement of incoherent motion of holes due to the t′ and t″ terms accounts for the formation of the flat region around (π,0) in the quasiparticle dispersion at underdoped and optimally doped region, despite the absence of the flat band at half filling. Our results are in excellent agreement with resent photoemission experiments on Bi 2 Sr 2 Ca 1 Cu 2 O 8+δ [Marshall et al., Phys. Rev. Lett.76, 4841 (1996)] and Sr 2 CuO 2 Cl 2 [Wells et al., Phys. Rev. Lett.74, 964 (1995)].

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Effects of two‐dimensional confinement on the optical properties of InGaAs/InP quantum wire structures

Applied Physics Letters ◽

10.1063/1.100052 ◽

1988 ◽

Vol 53 (11) ◽

pp. 995-997 ◽

Cited By ~ 135

Author(s):

D. Gershoni ◽

H. Temkin ◽

G. J. Dolan ◽

J. Dunsmuir ◽

S. N. G. Chu ◽

...

Keyword(s):

Optical Properties ◽

Quantum Wire ◽

Two Dimensional

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Kagome van-der-Waals Pd3P2S8 with flat band

Scientific Reports ◽

10.1038/s41598-020-77825-1 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Seunghyun Park ◽

Soonmin Kang ◽

Haeri Kim ◽

Ki Hoon Lee ◽

Pilkwang Kim ◽

...

Keyword(s):

Diamagnetic Susceptibility ◽

Van Der Waals ◽

Localized States ◽

Flat Band ◽

Two Dimensional ◽

Kagome Lattice ◽

Kagomé Lattice ◽

Localized State ◽

Low Dimensional ◽

Important Structure

AbstractWith the advanced investigations into low-dimensional systems, it has become essential to find materials having interesting lattices that can be exfoliated down to monolayer. One particular important structure is a kagome lattice with its potentially diverse and vibrant physics. We report a van-der-Waals kagome lattice material, Pd3P2S8, with several unique properties such as an intriguing flat band. The flat band is shown to arise from a possible compact-localized state of all five 4d orbitals of Pd. The diamagnetic susceptibility is precisely measured to support the calculated susceptibility obtained from the band structure. We further demonstrate that Pd3P2S8 can be exfoliated down to monolayer, which ultimately will allow the possible control of the localized states in this two-dimensional kagome lattice using the electric field gating.

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SPIN-DEPENDENT ELECTRON TRANSPORT IN A QUANTUM WIRE WITH FINITE WIDTH MODULATED BY MAGNETIC-ELECTRIC BARRIERS

International Journal of Modern Physics B ◽

10.1142/s021797921250138x ◽

2012 ◽

Vol 26 (26) ◽

pp. 1250138

Author(s):

JIAN-DUO LU ◽

BIN XU ◽

WEI ZHENG

Keyword(s):

Electron Transport ◽

Quantum Wire ◽

Electron Gas ◽

Transmission Probability ◽

Finite Width ◽

Two Dimensional ◽

Dimensional Electron ◽

Two Dimensional Electron Gas ◽

Dimensional Electron Gas ◽

Electric Barrier

We theoretically present the spin-dependent electron transport in a two-dimensional electron gas (2DEG) with finite width modulated by magnetic–electric barriers. It is found that the transmission probability and the spin polarization are strongly dependent on the height of the electric barrier, the energy of the incident electron, the distance between the two magnetic fields, and the width of the 2DEG. These may be useful for making the practical devices.

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