225 citations · 1.7k across the 33 of their papers we have counts for
19 papers · 1 filter
Robust Interlayer-Coherent Quantum Hall States in Twisted Bilayer Graphene
Dohun Kim, Byungmin Kang, Yong-Bin Choi +5
We introduce a novel two-dimensional electronic system with ultrastrong interlayer interactions, namely twisted bilayer graphene with a large twist angle, as an ideal ground for re…
Steady Floquet-Andreev States Probed by Tunnelling Spectroscopy
Sein Park, Wonjun Lee, Seong Jang +7
Engineering quantum states through light-matter interaction has created a new paradigm in condensed matter physics. A representative example is the Floquet-Bloch state, which is ge…
Spin-orbit Torque Switching in an All-Van der Waals Heterostructure
Inseob Shin, Won Joon Cho, Eun-Su An +14
Current-induced control of magnetization in ferromagnets using spin-orbit torque (SOT) has drawn attention as a new mechanism for fast and energy efficient magnetic memory devices.…
Strongly-bound excitons and trions in anisotropic 2D semiconductors
Sangho Yoon, Taeho Kim, Seung-Young Seo +9
Monolayer and few-layer phosphorene are anisotropic quasi-two-dimensional (quasi-2D) van der Waals (vdW) semiconductors with a linear-dichroic light-matter interaction and a widely…
Imaging Andreev Reflection in Graphene
S. Bhandari, G. -H. Lee, K. Watanabe +3
Coherent charge transport along ballistic paths can be introduced into graphene by Andreev reflection, for which an electron reflects from a superconducting contact as a hole, whil…
Imaging the Flow of Holes from a Collimating Contact in Graphene
Sagar Bhandari, Mary Kreidel, Alexander Kelser +5
A beam of holes formed in graphene by a collimating contact is imaged using a liquid-He cooled scanning probe microscope (SPM). The mean free path of holes is greater than the devi…
Evidence of Higher Order Topology in Multilayer WTe from Josephson Coupling through Anisotropic Hinge States
Yong-Bin Choi, Yingming Xie, Chui-Zhen Chen +12
The noncentrosymmetric Td-WTe, previously known as a type-II Weyl semimetal, is expected to have higher order topological phases with topologically protected, helical one-dimen…
Graphene-based Josephson junction microwave bolometer
Gil-Ho Lee, Dmitri K. Efetov, Woochan Jung +8
Sensitive microwave detectors are critical instruments in radioastronomy, dark matter axion searches, and superconducting quantum information science. The conventional strategy tow…
Impact of geometry and non-idealities on electron 'optics' based graphene p-n junction devices
Mirza M. Elahi, K. M. Masum Habib, Ke Wang +3
We articulate the challenges and opportunities of unconventional devices using the photon like flow of electrons in graphene, such as Graphene Klein Tunnel (GKT) transistors. The u…
Short Ballistic Josephson Coupling in Planar Graphene Junctions with Inhomogeneous Carrier Doping
Jinho Park, Jae Hyeong Lee, Gil-Ho Lee +5
We report on short ballistic (SB) Josephson coupling in junctions embedded in a planar heterostructure of graphene. Ballistic Josephson coupling is confirmed by the Fabry-Perot-typ…
Imaging electron flow from collimating contacts in graphene
Sagar Bhandari, Gil-Ho Lee, Kenji Watanabe +3
The ballistic motion of electrons in graphene encapsulated in hexagonal boron nitride (hBN) promises exciting opportunities for electron-optics devices. A narrow electron beam is d…
Proximity coupling in superconductor-graphene heterostructures
Gil-Ho Lee, Hu-Jong Lee
This review discusses the electronic properties and the prospective research directions of superconductor-graphene heterostructures. The basic electronic properties of graphene are…
Graphene-based Josephson junction single photon detector
Evan D. Walsh, Dmitri K. Efetov, Gil-Ho Lee +6
We propose to use graphene-based Josephson junctions (gJjs) to detect single photons in a wide electromagnetic spectrum from visible to radio frequencies. Our approach takes advant…
Inducing Superconducting Correlation in Quantum Hall Edge States
Gil-Ho Lee, Ko-Fan Huang, Dmitri K. Efetov +6
The quantum Hall (QH) effect supports a set of chiral edge states at the boundary of a 2-dimensional electron gas (2DEG) system. A superconductor (SC) contacting these states induc…
Analysis of Scanned Probe Images for Magnetic Focusing in Graphene
Sagar Bhandari, Gil-Ho Lee, Philip Kim +1
We use a cooled Scanning Probe Microscope (SPM) to electron motion in nanoscale devices. The charged tip of the SPM is raster scanned at a constant height above the surface as the…
Imaging Cyclotron Orbits of Electrons in Graphene
S. Bhandari, G. H. Lee, A. Klales +5
Electrons in graphene can travel for several microns without scattering at low temperatures, and their motion becomes ballistic, following classical trajectories. When a magnetic f…
Observation of negative refraction of Dirac fermions in graphene
Gil-Ho Lee, Geon-Hyoung Park, Hu-Jong Lee
Half a century ago, Veselago proposed left-handed materials with negative permittivity and permeability, in which waves propagate with phase and group velocities in opposite direct…
Electrically Tunable Macroscopic Quantum Tunneling in a Graphene-based Josephson Junction
Gil-Ho Lee, Dongchan Jeong, Jae-Hyun Choi +2
Stochastic switching-current distribution in a graphene-based Josephson junction exhibits a crossover from the classical to quantum regime, revealing the macroscopic quantum tunnel…
Observation of Supercurrent in PbIn-Graphene-PbIn Josephson Junction
Dongchan Jeong, Jae-Hyun Choi, Gil-Ho Lee +3
Superconductor-graphene-superconductor (SGS) junction provides a unique platform to study relativistic electrodynamics of Dirac fermions combined with proximity-induced superconduc…