447 citations · 1.8k across the 25 of their papers we have counts for
25 papers
Observation of Cavity-Mediated Nonlinear Landau Fan and Modified Landau Level Degeneracy in Graphene Quantum Transport
Hongxia Xue, Hsun-Chi Chan, Zuzhang Lin +9
Recent studies on cavity-coupled two-dimensional electron gas demonstrate that vacuum-field engineering can tailor electronic transport properties of materials. By achieving ultra-…
Coulomb drag in graphene/hBN/graphene moiré heterostructures
Yueyang Wang, Hongxia Xue, Xiong Wang +3
We report on the observation of Coulomb drag between graphene-hexagonal boron nitride (hBN) moiré heterostructure with a moiré wavelength of 14 nm and an intrinsic graphene w…
Landau-level spectrum and the effect of spin-orbit coupling in monolayer graphene on transition metal dichalcogenides
Qing Rao, Hongxia Xue, Dong-Keun Ki
In graphene on transition metal dichalcogenides, proximity-induced Rashba and spin-valley Zeeman SOCs can coexist that modify graphene's electronic band differently. Here, we show…
Scratching lithography, manipulation, and soldering of 2D materials using microneedle probes
Qing Rao, Guoyun Gao, Xinyu Wang +2
We demonstrate a facile technique to scratch, manipulate, and solder exfoliated flakes of layered 2D materials using a microneedle probe attached to the precision xyz manipulators…
Ballistic transport spectroscopy of spin-orbit-coupled bands in monolayer graphene on WSe
Qing Rao, Wun-Hao Kang, Hongxia Xue +7
Van der Waals interactions with transition metal dichalcogenides was shown to induce strong spin-orbit coupling (SOC) in graphene, offering great promises to combine large experime…
A Family of Finite-Temperature Electronic Phase Transitions in Graphene Multilayers
Youngwoo Nam, Dong-Keun Ki, David Soler-Delgado +1
Suspended Bernal-stacked graphene multilayers up to an unexpectedly large thickness exhibit a broken-symmetry ground state, whose origin remains to be understood. Here we show that…
Controlling the topological sector of magnetic solitons in exfoliated CrNbS crystals
L. Wang, N. Chepiga, D. -K. Ki +9
We investigate manifestations of topological order in monoaxial helimagnet CrNbS by performing transport measurements on ultra-thin crystals. Upon sweeping the magnetic…
Electron-hole collision limited transport in charge-neutral bilayer graphene
Youngwoo Nam, Dong-Keun Ki, David Soler-Delgado +1
Ballistic transport occurs whenever electrons propagate without collisions deflecting their trajectory. It is normally observed in conductors with a negligible concentration of imp…
Interaction-induced insulating state in thick multilayer graphene
Youngwoo Nam, Dong-Keun Ki, Mikito Koshino +2
Close to charge neutrality, the low-energy properties of high-quality suspended devices based on atomically thin graphene layers are determined by electron-electron interactions. B…
Origin and magnitude of 'designer' spin-orbit interaction in graphene on semiconducting transition metal dichalcogenides
Zhe Wang, Dong-Keun Ki, Jun Yong Khoo +4
We use a combination of experimental techniques to demonstrate a general occurrence of spin-orbit interaction (SOI) in graphene on transition metal dichalcogenide (TMD) substrates.…
Direct Observation of Long-range field-effect from gate tuning of non-local conductivity
Lin Wang, Ignacio Gutiérrez-Lezama, Céline Barreteau +3
We report the observation of an unexpected, long-range field-effect in WTe devices, leading to large gate-induced changes of the transport properties of crystals much thicker t…
Strong interface-induced spin-orbit coupling in graphene on WS2
Zhe Wang, Dong-Keun Ki, Hua Chen +3
Interfacial interactions allow the electronic properties of graphene to be modified, as recently demonstrated by the appearance of satellite Dirac cones in the band structure of gr…
Insulating state in tetralayers reveals an even-odd interaction effect in multilayer graphene
Anya L. Grushina, Dong-Keun Ki, Mikito Koshino +5
The absence of an energy gap separating valence and conduction bands makes the low-energy electronic properties of graphene and its multi-layers sensitive to electron-electron inte…
High-quality multi-terminal suspended graphene devices
Dong-Keun Ki, Alberto F. Morpurgo
We introduce a new scheme to realize suspended, multi-terminal graphene structures that can be current annealed successfully to obtain uniform, very high quality devices. A key asp…
Random strain fluctuations as dominant disorder source for high-quality on-substrate graphene devices
Nuno J. G. Couto, Davide Costanzo, Stephan Engels +6
We have performed systematic investigations of transport through graphene on hexagonal boron nitride (hBN) substrates, together with confocal Raman measurements and a targeted theo…
Observation of even denominator fractional quantum Hall effect in suspended bilayer graphene
Dong-Keun Ki, Vladimir I. Fal'ko, Dmitry A. Abanin +1
We investigate low-temperature magneto-transport in recently developed, high-quality multi-terminal suspended bilayer graphene devices, enabling the independent measurement of the…
A ballistic pn junction in suspended graphene with split bottom gates
Anya L. Grushina, Dong-Keun Ki, Alberto F. Morpurgo
We have developed a process to fabricate suspended graphene devices with local bottom gates, and tested it by realizing electrostatically controlled pn junctions on a suspended gra…
Identification of a strong contamination source for graphene in vacuum systems
Christophe Caillier, Dong-Keun Ki, Yuliya Lisunova +3
To minimize parasitic doping effects caused by uncontrolled material adsorption, graphene is often investigated under vacuum. Here we report an entirely unexpected phenomenon occur…
Crossover from Coulomb blockade to quantum Hall effect in suspended graphene nanoribbons
Dong-Keun Ki, Alberto F. Morpurgo
Suspended graphene nano-ribbons formed during current annealing of suspended graphene flakes have been investigated experimentally. Transport measurements show the opening of a tra…
Ballistic transport of graphene pnp junctions with embedded local gates
Seung-Geol Nam, Dong-Keun Ki, Jong Wan Park +3
We fabricated graphene pnp devices, by embedding pre-defined local gates in an oxidized surface layer of a silicon substrate. With neither dielectric-material deposition nor electr…
Thermoelectric Transport of Massive Dirac Fermions in Bilayer Graphene
Seung-Geol Nam, Dong-Keun Ki, Hu-Jong Lee
Thermoelectric power (TEP) is measured in bilayer graphene for various temperatures and charge-carrier densities. At low temperatures, measured TEP well follows the semiclassical M…
Dependence of quantum-Hall conductance on the edge-state equilibration position in a bipolar graphene sheet
Dong-Keun Ki, Seung-Geol Nam, Hu-Jong Lee +1
By using four-terminal configurations, we investigated the dependence of longitudinal and diagonal resistances of a graphene p-n interface on the quantum-Hall edge-state equilibrat…
Observation of chiral quantum-Hall edge states in graphene
Dong-Keun Ki, Sanghyun Jo, Hu-Jong Lee
In this study, we determined the chiral direction of the quantum-Hall (QH) edge states in graphene by adopting simple two-terminal conductance measurements while grounding differen…
Quantum Hall resistances of multiterminal top-gated graphene device
Dong-Keun Ki, Hu-Jong Lee
Four-terminal resistances, both longitudinal and diagonal, of a locally gated graphene device are measured in the quantum-Hall (QH) regime. In sharp distinction from previous two-t…