352 citations · 2k across the 34 of their papers we have counts for
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Observation of Giant Orbital Magnetic Moments and Paramagnetic Shift in Artificial Relativistic Atoms and Molecules
Zhehao Ge, Sergey Slizovskiy, Peter Polizogopoulos +6
Massless Dirac fermions have been observed in various materials such as graphene and topological insulators in recent years, thus offering a solid-state platform to study relativis…
Imaging Quantum Interference in Stadium-Shaped Monolayer and Bilayer Graphene Quantum Dots
Zhehao Ge, Dillon Wong, Juwon Lee +10
Experimental realization of graphene-based stadium-shaped quantum dots (QDs) have been few and incompatible with scanned probe microscopy. Yet, direct visualization of electronic s…
Ultra-sharp lateral junctions in modulation-doped graphene
Jesse Balgley, Jackson Butler, Sananda Biswas +9
We demonstrate ultra-sharp () lateral junctions in graphene using electronic transport, scanning tunneling microscopy, and first principles c…
Quasiparticle interference patterns in bilayer graphene with trigonal warping
Vardan Kaladzhyan, Frédéric Joucken, Zhehao Ge +5
We calculate the form of quasiparticle interference patterns in bilayer graphene within a low-energy description, taking into account perturbatively the trigonal warping terms. We…
Surface states and quasiparticle interference in Bernal and rhombohedral graphite with and without trigonal warping
Vardan Kaladzhyan, Sarah Pinon, Frédéric Joucken +6
We use an exact analytical technique [Phys. Rev. B \textbf{101}, 115405 (2020), Phys. Rev. B \textbf{102}, 165117 (2020)] to recover the surface Green's functions for Bernal (ABA)…
Sublattice dependence and gate-tunability of midgap and resonant states induced by native dopants in Bernal-stacked bilayer graphene
Frédéric Joucken, Cristina Bena, Zhehao Ge +5
The properties of semiconductors can be crucially impacted by midgap states induced by dopants, which can be native or intentionally incorporated in the crystal lattice. For Bernal…
Direct Visualization of Native Defects in Graphite and Their Effect on the Electronic Properties of Bernal-Stacked Bilayer Graphene
Frederic Joucken, Cristina Bena, Zhehao Ge +7
Graphite crystals used to prepare graphene-based heterostructures are generally assumed to be defect free. We report here scanning tunneling microscopy results that show graphite c…
Control of Giant Topological Magnetic Moment and Valley Splitting in Trilayer Graphene
Zhehao Ge, Sergey Slizovskiy, Fredric Joucken +5
Bloch states of electrons in honeycomb two-dimensional crystals with multi-valley band structure and broken inversion symmetry have orbital magnetic moments of a topological nature…
Visualization and Manipulation of Bilayer Graphene Quantum Dots with Broken Rotational Symmetry and Nontrivial Topology
Zhehao Ge, Frederic Joucken, Eberth Quezada +8
Electrostatically defined quantum dots (QDs) in Bernal stacked bilayer graphene (BLG) are a promising quantum information platform because of their long spin decoherence times, hig…
Gate Tunable Magnetism and Giant Magnetoresistance in ABC-stacked Few-Layer Graphene
Yongjin Lee, Shi Che, Jairo Velasco +6
Magnetism is a prototypical phenomenon of quantum collective state, and has found ubiquitous applications in semiconductor technologies such as dynamic random access memory (DRAM).…
Determination of the trigonal warping orientation in Bernal-stacked bilayer graphene via scanning tunneling microscopy
Frédéric Joucken, Zhehao Ge, Eberth A. Quezada-López +4
The existence of strong trigonal warping around the K point for the low energy electronic states in multilayer (N2) graphene films and graphite is well established. It is res…
Probing the Electronic Structure of Graphene Near and Far from the Fermi Level via Planar Tunneling Spectroscopy
John L. Davenport, Zhehao Ge, Junyan Liu +12
Scanning tunneling spectroscopy (STS) has yielded significant insight on the electronic structure of graphene and other two-dimensional (2D) materials. STS directly measures a fund…
Visualization and Control of Single Electron Charging in Bilayer Graphene Quantum Dots
Jairo Velasco, Juwon Lee, Dillon Wong +9
Graphene p-n junctions provide an ideal platform for investigating novel behavior at the boundary between electronics and optics that arise from massless Dirac fermions, such as wh…
Imaging electrostatically confined Dirac fermions in graphene quantum dots
Juwon Lee, Dillon Wong, Jairo Velasco +9
Electrostatic confinement of charge carriers in graphene is governed by Klein tunneling, a relativistic quantum process in which particle-hole transmutation leads to unusual anisot…
Nanoscale control of rewriteable doping patterns in pristine graphene/boron nitride heterostructures
Jairo Velasco, Long Ju, Dillon Wong +11
Nanoscale control of charge doping in two-dimensional (2D) materials permits the realization of electronic analogs of optical phenomena, relativistic physics at low energies, and t…
Characterization and manipulation of individual defects in insulating hexagonal boron nitride using scanning tunneling microscopy
Dillon Wong, Jairo Velasco, Long Ju +9
Defects play a key role in determining the properties of most materials and, because they tend to be highly localized, characterizing them at the single-defect level is particularl…
Distinct Competing Ordered ν=2 States in Bilayer Graphene
J. Velasco, Y. Lee, Fan Zhang +6
Because of its large density-of-states and the 2π Berry phase near its low-energy band-contact points, neutral bilayer graphene (BLG) at zero magnetic field (B) is susceptible to c…
Giant Interaction-Induced Gap and Electronic Phases in Rhombohedral Trilayer Graphene
Y. Lee, D. Tran, K. Myhro +7
Due to their unique electron dispersion and lack of a Fermi surface, Coulomb interactions in undoped two-dimensional Dirac systems, such as single, bi- and tri-layer graphene, can…
Photo-induced Doping in Graphene/Boron Nitride Heterostructures
L. Ju, J. Velasco, E. Huang +11
The design of stacks of layered materials in which adjacent layers interact by van der Waals forces[1] has enabled the combination of various two-dimensional crystals with differen…
Transport Measurement of Landau level Gaps in Bilayer Graphene
J. Velasco, Y. Lee, Z. Zhao +4
Landau level gaps are important parameters for understanding electronic interactions and symmetry-broken processes in bilayer graphene (BLG). Here we present transport spectroscopy…
Broken Symmetry Quantum Hall States in Dual Gated ABA Trilayer Graphene
Yongjin Lee, Jairo Velasco, David Tran +6
We present low temperature transport measurements on dual-gated suspended trilayer graphene in the quantum Hall (QH) regime. We observe QH plateaus at filling factors ν=-8, -2, 2,…
Minimum Conductivity and Evidence for Phase Transitions in Ultra-clean Bilayer Graphene
Wenzhong Bao, Jairo Velasco, Fan Zhang +6
Bilayer graphene (BLG) at the charge neutrality point (CNP) is strongly susceptible to electronic interactions, and expected to undergo a phase transition into a state with spontan…
Transport Spectroscopy of Symmetry-Broken Insulating States in Bilayer Graphene
J. Velasco, L. Jing, W. Bao +11
The flat bands in bilayer graphene(BLG) are sensitive to electric fields E\bot directed between the layers, and magnify the electron-electron interaction effects, thus making BLG a…
Suspension and Measurement of Graphene and Bi2Se3 Atomic Membranes
Jairo Velasco, Zeng Zhao, Hang Zhang +7
Coupling high quality, suspended atomic membranes to specialized electrodes enables investigation of many novel phenomena, such as spin or Cooper pair transport in these two dimens…