(a) Sketch of a graphene bilayer with angle θ between top and bottom
A representative illustration of bilayer graphene with different
(a) Top view of graphene bilayer structure with an interlayer
a Crystal structure of Bernal-stacked bilayer graphene showing the
These schematics of the structures of bilayer graphene in (a) AA, (b
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Defensa TFG María Fernanda Quesada Mena
Understanding Bilayer Graphene
Theory Winter School 2024: Stevan Nadj Perge
Talks
Dirac points near the first magic angle in twisted bilayer graphene
Tight Binding Calculation of the Graphene Band Structure: Transfer and Overlap Matrix Elements (UP)
COMMENTS
Study Of electronic correlation and superconductivity in twisted
Furthermore, it is found that both the superconducting and normal state in magic-angle twisted bilayer graphene exhibit significant anisotropy, likely as a result of the electronic correlations as well. I also present results in twisted graphene superlattices beyond twisted bilayer graphene. These studies might help us understand more about the ...
PDF Electronic Transport in Low-Angle Twisted Bilayer Graphene
In this work, a novel tear-and-stack technique is developed to reliably produce twisted bilayer graphene with controlled angle, and electronic transport measure-ments of the resulting high-quality samples are performed and discussed. We dis-cover novel insulating states that purely results from the moife superlattice band structure. The magnetotransport properties of these insulating states ...
Superconductivity in Graphene Hetero-Structures: From Fundamental
In 2018, an astonishing discovery showed that by placing two sheets of graphene on top of each other in a structure known as Twisted Bilayer Graphene, it is possible to realize superconductivity when the rotation angle between the sheets is close to the "Magic Angle" value of 1.1°.
Unique Electronic Properties of the Twisted Bilayer Graphene
Graphene is the first experimentally discovered two-dimensional material. This article reviews the unique properties of the so-called twisted bilayer graphene (TBG), which can be considered a superstructure formed by stacking two graphene layers with a specific twisting angle.
Electronic transport in low-angle twisted bilayer graphene
In this work, a novel tear-and-stack technique is developed to reliably produce twisted bilayer graphene with controlled angle, and electronic transport measurements of the resulting high-quality samples are performed and discussed. We discover novel insulating states that purely results from the moiŕe superlattice band structure.
Graphene bilayers with a twist
Magic-angle twisted bilayer graphene plays host to many interesting phenomena, including superconductivity. This Review highlights key research results in the field, points toward important open ...
Twisted Bilayer Graphene: A Journey Through Recent Advances and Future
Twisted bilayer graphene (TBG) has emerged as a fascinating research frontier in condensed matter physics and materials science. This review article comprehensively overviews recent advances and future perspectives in studying TBG.
Twisted bilayer graphene: low-energy physics, electronic and optical
Twisted bilayer graphene (tBLG), a simple vdW structure where the interference between two misaligned graphene lattices leads to the formation of a moiré pattern, is a test bed to study the effects of the interaction and misalignment between layers, key players for determining the electronic properties of these stackings.
Fabrication and electrical transport properties of twisted bilayer
In this master thesis, a fabrication process for the creation of twisted bilayer graphene devices is developed and presented. Twisted bilayer graphene encapsulated in hexagonal boron nitride samples were created from scratch and characterized optically and with Raman spectroscopy. The process is based on dry transfer of exfoliated graphene and ...
Topology and correlations in twisted bilayer graphene
This thesis studies several examples of how topology and interactions lead to novel electronic phenomena in magic-angle twisted bilayer graphene, a moire heterostructure that has attracted much attention owing its diversity of experimentally-observed correlated phases.
Layer skyrmions for ideal Chern bands and twisted bilayer graphene
The topologically robust Skyrme texture remains remarkably intact in twisted bilayer graphene, even far from the chiral limit, and for realistic values of corrugation, making it an experimentally testable feature. We verify our predictions at the first magic angle of twisted bilayer, trilayer, and monolayer-bilayer graphene. ...
Electronic transport in twisted double bilayer graphene
Two Bernal stacked bilayer graphene sheets twisted relative to each other, i.e., twisted double bilayer graphene, gives the additional opportunity of tuning the electronic structure by a displacement electric eld. This thesis presents the fabrication and electrical transport measurements of twisted double bilayer graphene de-vices.
PDF Electronic and Optical Properties of Twisted Bilayer Graphene
This thesis presents the e orts to explore the electronic and optical properties of twisted bilayer graphene by Raman spectroscopy and scanning tunneling microscopy mea-surements. We rst synthesize twisted bilayer graphene with various twist angles via chem-ical vapor deposition.
Twisted bilayer graphene. I. Matrix elements, approximations
The physics of twisted bilayer graphene (TBG) is a complicated m\\'elange of topology and interactions. A unified understanding of the correlated insulators in TBG emerges in this series of six papers (TBG1--TBG6). Starting from the physics of single-particle bands, TBG1 simplifies the physics of the infinite dimensional Bistritzer-Macdonald Hamiltonian to that of a 12-site model. TBG2 ...
Commensurate and Incommensurate Chern Insulators in Magic-angle Bilayer
The interplay between strong electron-electron interaction and symmetry breaking can have profound influence on the topological properties of materials. In magic angle twisted bilayer graphene (MATBG), the flat band with a single SU(4) flavor associated with the spin and valley degrees of freedom gains non-zero Chern number when C2z symmetry or C2zT symmetry is broken. Electron-electron ...
DataSpace: Electronic Correlations, Topology, and Unconventional
Items in Dataspace are protected by copyright, with all rights reserved, unless otherwise indicated.
Fermionic Monte Carlo Study of a Realistic Model of Twisted Bilayer
New realistic models of twisted bilayer graphene avoid a key limitation of other models, allowing for exact simulations of hundreds of electrons over a wide range of temperatures.
DataSpace: Modelling, Fabrication and Characterisation of Twisted
Items in Dataspace are protected by copyright, with all rights reserved, unless otherwise indicated.
PDF Characterization of Magic-angle Twisted Bilayer Graphene using
Abstract Magic-angle twisted bilayer graphene (MATBG) is a highly tunable material platform that exhibits a wide range of novel phases, including correlated insulating states and unconventional superconductivity. Its tunability and potentially high kinetic induc-tance in the superconducting state are desirable properties for high-coherence, small-form-factor superconducting qubits. This thesis ...
PDF Quantum Oscillations in Twisted Bilayer Graphene
In this thesis, we have obtained the energy spectrum of twisted bilayer graphene (TBG) numeri-cally using the model from ref. [2], from which we made an analytical approximation.
Twisted Bilayer Graphene: Low‐Energy Physics, Electronic and Optical
This chapter contains sections titled: Introduction Basics of Monolayer and Bilayer Graphene Twisted Bilayer Graphene
Physical Review B
Our calculations are based on classical fluid dynamics equations derived from the Boltzmann equation for bilayer graphene in [1], and suggest that while this resonance is accessible to current experimental techniques, the same mechanism which causes the hydrodynamic resonance to differ from the Fermi liquid value is responsible for a ...
'Kink states' regulate the flow of electrons in graphene
Bernal bilayer graphene consists of two atomically-thin sheets of carbon stacked on top of each other and shifted slightly. This arrangement gives rise to several unusual electronic behaviours. One such behaviour, known as the quantum valley Hall effect, gets its name from the dips or "valleys" that appear in graphs of an electron's ...
Dissertations / Theses: 'Graphene Bilayers'
Bilayer graphene (2LG) and trilayer graphene (3LG) share many of the interesting properties of its monolayer relative, but with several key differences. This thesis makes use of resonant Raman spectroscopy to characterize these systems and quantify their layer number as well as stacking order in different graphene flakes.
Electronic transport in low-angle twisted bilayer graphene
In this work, a novel tear-and-stack technique is developed to reliably produce twisted bilayer graphene with controlled angle, and electronic transport measurements of the resulting high-quality samples are performed and discussed. We discover novel insulating states that purely results from the moiŕe superlattice band structure.
Phys. Rev. B 110, 075147 (2024)
The external magnetic field normal to the graphene sample allows separating hot and cold currents in real space. The developed formalism may help interpreting the recent experimental data on ballistic edge currents in graphene bilayers in the quantum Hall regime [J. Barrier et al., Nature (London) 628, 741 (2024)].
PDF Studies of bilayer and trilayer graphene
Bilayer graphene (2LG) and trilayer graphene (3LG) share many of the interesting properties of its monolayer relative, but with several key differences. This thesis makes use of resonant Raman spectroscopy to characterize these systems and quantify their layer number as well as stacking order in different graphene flakes.
Studies of bilayer and trilayer graphene
Bilayer graphene (2LG) and trilayer graphene (3LG) share many of the interesting properties of its monolayer relative, but with several key differences. This thesis makes use of resonant Raman spectroscopy to characterize these systems and quantify their layer number as well as stacking order in different graphene flakes.
IMAGES
VIDEO
COMMENTS
Furthermore, it is found that both the superconducting and normal state in magic-angle twisted bilayer graphene exhibit significant anisotropy, likely as a result of the electronic correlations as well. I also present results in twisted graphene superlattices beyond twisted bilayer graphene. These studies might help us understand more about the ...
In this work, a novel tear-and-stack technique is developed to reliably produce twisted bilayer graphene with controlled angle, and electronic transport measure-ments of the resulting high-quality samples are performed and discussed. We dis-cover novel insulating states that purely results from the moife superlattice band structure. The magnetotransport properties of these insulating states ...
In 2018, an astonishing discovery showed that by placing two sheets of graphene on top of each other in a structure known as Twisted Bilayer Graphene, it is possible to realize superconductivity when the rotation angle between the sheets is close to the "Magic Angle" value of 1.1°.
Graphene is the first experimentally discovered two-dimensional material. This article reviews the unique properties of the so-called twisted bilayer graphene (TBG), which can be considered a superstructure formed by stacking two graphene layers with a specific twisting angle.
In this work, a novel tear-and-stack technique is developed to reliably produce twisted bilayer graphene with controlled angle, and electronic transport measurements of the resulting high-quality samples are performed and discussed. We discover novel insulating states that purely results from the moiŕe superlattice band structure.
Magic-angle twisted bilayer graphene plays host to many interesting phenomena, including superconductivity. This Review highlights key research results in the field, points toward important open ...
Twisted bilayer graphene (TBG) has emerged as a fascinating research frontier in condensed matter physics and materials science. This review article comprehensively overviews recent advances and future perspectives in studying TBG.
Twisted bilayer graphene (tBLG), a simple vdW structure where the interference between two misaligned graphene lattices leads to the formation of a moiré pattern, is a test bed to study the effects of the interaction and misalignment between layers, key players for determining the electronic properties of these stackings.
In this master thesis, a fabrication process for the creation of twisted bilayer graphene devices is developed and presented. Twisted bilayer graphene encapsulated in hexagonal boron nitride samples were created from scratch and characterized optically and with Raman spectroscopy. The process is based on dry transfer of exfoliated graphene and ...
This thesis studies several examples of how topology and interactions lead to novel electronic phenomena in magic-angle twisted bilayer graphene, a moire heterostructure that has attracted much attention owing its diversity of experimentally-observed correlated phases.
The topologically robust Skyrme texture remains remarkably intact in twisted bilayer graphene, even far from the chiral limit, and for realistic values of corrugation, making it an experimentally testable feature. We verify our predictions at the first magic angle of twisted bilayer, trilayer, and monolayer-bilayer graphene. ...
Two Bernal stacked bilayer graphene sheets twisted relative to each other, i.e., twisted double bilayer graphene, gives the additional opportunity of tuning the electronic structure by a displacement electric eld. This thesis presents the fabrication and electrical transport measurements of twisted double bilayer graphene de-vices.
This thesis presents the e orts to explore the electronic and optical properties of twisted bilayer graphene by Raman spectroscopy and scanning tunneling microscopy mea-surements. We rst synthesize twisted bilayer graphene with various twist angles via chem-ical vapor deposition.
The physics of twisted bilayer graphene (TBG) is a complicated m\\'elange of topology and interactions. A unified understanding of the correlated insulators in TBG emerges in this series of six papers (TBG1--TBG6). Starting from the physics of single-particle bands, TBG1 simplifies the physics of the infinite dimensional Bistritzer-Macdonald Hamiltonian to that of a 12-site model. TBG2 ...
The interplay between strong electron-electron interaction and symmetry breaking can have profound influence on the topological properties of materials. In magic angle twisted bilayer graphene (MATBG), the flat band with a single SU(4) flavor associated with the spin and valley degrees of freedom gains non-zero Chern number when C2z symmetry or C2zT symmetry is broken. Electron-electron ...
Items in Dataspace are protected by copyright, with all rights reserved, unless otherwise indicated.
New realistic models of twisted bilayer graphene avoid a key limitation of other models, allowing for exact simulations of hundreds of electrons over a wide range of temperatures.
Items in Dataspace are protected by copyright, with all rights reserved, unless otherwise indicated.
Abstract Magic-angle twisted bilayer graphene (MATBG) is a highly tunable material platform that exhibits a wide range of novel phases, including correlated insulating states and unconventional superconductivity. Its tunability and potentially high kinetic induc-tance in the superconducting state are desirable properties for high-coherence, small-form-factor superconducting qubits. This thesis ...
In this thesis, we have obtained the energy spectrum of twisted bilayer graphene (TBG) numeri-cally using the model from ref. [2], from which we made an analytical approximation.
This chapter contains sections titled: Introduction Basics of Monolayer and Bilayer Graphene Twisted Bilayer Graphene
Our calculations are based on classical fluid dynamics equations derived from the Boltzmann equation for bilayer graphene in [1], and suggest that while this resonance is accessible to current experimental techniques, the same mechanism which causes the hydrodynamic resonance to differ from the Fermi liquid value is responsible for a ...
Bernal bilayer graphene consists of two atomically-thin sheets of carbon stacked on top of each other and shifted slightly. This arrangement gives rise to several unusual electronic behaviours. One such behaviour, known as the quantum valley Hall effect, gets its name from the dips or "valleys" that appear in graphs of an electron's ...
Bilayer graphene (2LG) and trilayer graphene (3LG) share many of the interesting properties of its monolayer relative, but with several key differences. This thesis makes use of resonant Raman spectroscopy to characterize these systems and quantify their layer number as well as stacking order in different graphene flakes.
In this work, a novel tear-and-stack technique is developed to reliably produce twisted bilayer graphene with controlled angle, and electronic transport measurements of the resulting high-quality samples are performed and discussed. We discover novel insulating states that purely results from the moiŕe superlattice band structure.
The external magnetic field normal to the graphene sample allows separating hot and cold currents in real space. The developed formalism may help interpreting the recent experimental data on ballistic edge currents in graphene bilayers in the quantum Hall regime [J. Barrier et al., Nature (London) 628, 741 (2024)].
Bilayer graphene (2LG) and trilayer graphene (3LG) share many of the interesting properties of its monolayer relative, but with several key differences. This thesis makes use of resonant Raman spectroscopy to characterize these systems and quantify their layer number as well as stacking order in different graphene flakes.
Bilayer graphene (2LG) and trilayer graphene (3LG) share many of the interesting properties of its monolayer relative, but with several key differences. This thesis makes use of resonant Raman spectroscopy to characterize these systems and quantify their layer number as well as stacking order in different graphene flakes.