scholarly journals Some peculiarities of thermopower at the Lifshitz topological transitions due to stacking change in bilayer and multilayer graphene

2019 ◽  
Vol 475 (2226) ◽  
pp. 20190028 ◽  
Author(s):  
V. N. Davydov
Keyword(s):  
Seebeck Coefficient ◽  
Electronic Properties ◽  
Chemical Potential ◽  
Bilayer Graphene ◽  
Multilayer Graphene ◽  
Gapped Graphene ◽  
Topological Transitions

Singularities of thermopower (the Seebeck coefficient) are considered at the Lifshitz topological transitions (LTT) in bilayer graphene (BLG) and multilayer graphene (MLG) due to stacking change from AB to AA . The dependence of singularities on μ , γ 1 and Δ is investigated ( μ is the chemical potential, γ 1 is the interlayer hopping parameter and Δ is the gap value) for the gapped graphene, as well as for the gapless one. The present paper results indicate that effects of the thermopower singularities are appreciable and can be used to observe the LTT, and to explore the degree of stacking change from AB to AA in graphene. Therefore, the thermopower singularities at LTT due to stacking change from AB to AA can be used as a powerful tool to control electronic properties of BLG- and MLG-based structures.

scholarly journals Chemical potential and quantum Hall ferromagnetism in bilayer graphene

Science ◽  
2014 ◽  
Vol 345 (6192) ◽  
pp. 58-61 ◽  
Author(s):  
Kayoung Lee ◽  
Babak Fallahazad ◽  
Jiamin Xue ◽  
David C. Dillen ◽  
Kyounghwan Kim ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Chemical Potential ◽  
Hexagonal Boron Nitride ◽  
Quantum Hall ◽  
Bilayer Graphene ◽  
Zero Magnetic Field ◽  
High Magnetic Fields ◽  
Complex Interplay ◽  
Electron Hole ◽  
Quantum Hall State

Bilayer graphene has a distinctive electronic structure influenced by a complex interplay between various degrees of freedom. We probed its chemical potential using double bilayer graphene heterostructures, separated by a hexagonal boron nitride dielectric. The chemical potential has a nonlinear carrier density dependence and bears signatures of electron-electron interactions. The data allowed a direct measurement of the electric field–induced bandgap at zero magnetic field, the orbital Landau level (LL) energies, and the broken-symmetry quantum Hall state gaps at high magnetic fields. We observe spin-to-valley polarized transitions for all half-filled LLs, as well as emerging phases at filling factors ν = 0 and ν = ±2. Furthermore, the data reveal interaction-driven negative compressibility and electron-hole asymmetry in N = 0, 1 LLs.

scholarly journals Tunable s-SNOM for Nanoscale Infrared Optical Measurement of Electronic Properties of Bilayer Graphene

ACS Photonics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 418-423
Author(s):  
Konstantin G. Wirth ◽  
Heiko Linnenbank ◽  
Tobias Steinle ◽  
Luca Banszerus ◽  
Eike Icking ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Optical Measurement ◽  
Bilayer Graphene

scholarly journals Tunable Coupled-Resonator-Induced Transparency in a Photonic Crystal System Based on a Multilayer-Insulator Graphene Stack

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2042 ◽  
Author(s):  
Hanqing Liu ◽  
Jianfeng Tan ◽  
Peiguo Liu ◽  
Li-an Bian ◽  
Song Zha
Keyword(s):  
Photonic Crystal ◽  
Optical Sensors ◽  
Chemical Potential ◽  
Structural Parameters ◽  
Multilayer Graphene ◽  
Crystal System ◽  
Chemical Potentials ◽  
Nonlinear Devices ◽  
Induced Transparency ◽  
Coupled Resonator

We achieve the effective modulation of coupled-resonator-induced transparency (CRIT) in a photonic crystal system which consists of photonic crystal waveguide (PCW), defect cavities, and a multilayer graphene-insulator stack (MGIS). Simulation results show that the wavelength of transparency window can be effectively tuned through varying the chemical potential of graphene in MGIS. The peak value of the CRIT effect is closely related to the structural parameters of our proposed system. Tunable Multipeak CRIT is also realized in the four-resonator-coupled photonic crystal system by modulating the chemical potentials of MGISs in different cavity units. This system paves a novel way toward multichannel-selective filters, optical sensors, and nonlinear devices.

Calculation of electronic properties of multilayer graphene with Monte Carlo method

2016 ◽  
Author(s):  
Ö. Atasever ◽  
M. D. Özdemir ◽  
B. Özdemir ◽  
Z. Yarar ◽  
M. Özdemir
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Electronic Properties ◽  
Multilayer Graphene

scholarly journals Study of Vacancies and Pd Atom Decoration on the Electronic Properties of Bilayer Graphene

2010 ◽  
Vol 23 (8) ◽  
pp. 1543-1550 ◽  
Author(s):  
D. H. Galvan ◽  
A. Posada Amarillas ◽  
R. Núñez-González ◽  
S. Mejía ◽  
M. José-Yacamán
Keyword(s):  
Electronic Properties ◽  
Bilayer Graphene

scholarly journals Electronic Properties of Twisted Bilayer Graphene in the Presence of a Magnetic Field

2020 ◽  
Vol 233 ◽  
pp. 03004
Author(s):  
M.F.C. Martins Quintela ◽  
J.C.C. Guerra ◽  
S.M. João
Keyword(s):  
Magnetic Field ◽  
Electronic Properties ◽  
Twist Angle ◽  
Bilayer Graphene ◽  
Polynomial Method ◽  
Zero Energy ◽  
Energy Bands ◽  
Optical And Electronic Properties ◽  
Twisted Bilayer Graphene ◽  
Kernel Polynomial Method

In AA-stacked twisted bilayer graphene, the lower energy bands become completely flat when the twist angle passes through certain specific values: the so-called “magic angles”. The Dirac peak appears at zero energy due to the flattening of these bands when the twist angle is sufficiently small [1-3]. When a constant perpendicular magnetic field is applied, Landau levels start appearing as expected [5]. We used the Kernel Polynomial Method (KPM) [6] as implemented in KITE [7] to study the optical and electronic properties of these systems. The aim of this work is to analyze how the features of these quantities change with the twist angle in the presence of an uniform magnetic field.

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