Related papers: Directional photoelectric current across the bilay…
We propose an implementation of a valley selective electronic Veselago lens in bilayer graphene. We demonstrate that in the presence of an appropriately oriented potential step, low-energy electrons radiating from a point source can be…
Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize…
We report the study of the helicity driven photocurrents in graphene excited by mid-infrared light of a CO$_2$-laser. Illuminating an unbiased monolayer sheet of graphene with circularly polarized radiation generates -- under oblique…
The bulk photovoltaic effect provides a fundamental pathway for direct light-to-current conversion in quantum materials. However, these nonlinear currents are often strictly constrained or forbidden by crystal symmetries, hindering their…
Klein tunneling in gapless bilayer graphene, perfect reflection of electrons injecting normal to a pn junction, is expected to disappear in the presence of energy band gap induced by external gates. We theoretically show that the Klein…
Periodically driven systems can host many interesting and intriguing phenomena. The irradiated two-dimensional Dirac systems, driven by circularly polarized light, are the most attractive thanks to intuitive physical view of the absorption…
Electronic properties of bilayer and multilayer graphene have generally been interpreted in terms of AB or Bernal stacking. However, it is known that many types of stacking defects can occur in natural and synthetic graphite; rotation of…
We report experimental signatures of plasmonic effects due to electron tunneling between adjacent graphene layers. At sub-nanometer separation, such layers can form either a strongly coupled bilayer graphene with a Bernal stacking or a…
We theoretically investigate the electron tunneling in dual-gated bilayer graphene-based $n/p$ junctions. It is shown that a band gap is introduced by tuning the gate voltage, which modifies the pseudospin polarization and breaks anti-Klein…
An intersection between one-dimensional chiral acts as a topological current splitter. We find that the splitting of a chiral zero-line mode obeys very simple, yet highly counterintuitive, partition laws which relate current paths to the…
Theory of the Linear photogalvanic effect is developed for direct optical transitions between surface states of three-dimensional topological insulators. The photocurrent governed by the orientation of the polarization plane of light and…
Electron's tunneling through potential barrier in monolayer and bilayer graphene lattices is investigated by using full tight-binding model. Emphasis is placed on the resonance tunneling feature and inter-valley scattering probability. It…
The ground state of a graphene sheet at charge neutrality in a perpendicular magnetic field remains enigmatic, with various experiments supporting canted antiferromagnetic, bond ordered, and even charge density wave phases. A promising…
We demonstrate theoretically that the topology of energy bands and Fermi surface in bilayer graphene undergoes a very sensitive transition when extremely tiny lateral interlayer shift occurs in arbitrary directions. The phenomenon…
The recent synthesis of two-dimensional staggered materials opens up burgeoning opportunities to study optical spin-orbit interactions in semiconducting Dirac-like systems. We unveil topological phase transitions in the photonic spin Hall…
We report on the observation of the nonlinear intensity dependence of the bulk photogalvanic current and photoconductivity in the twisted graphene with small twist angles close to the second magical angle. We show that terahertz radiation…
The control of charges in a circuit due to an external electric field is ubiquitous to the exchange, storage and manipulation of information in a wide range of applications, from electronic circuits to synapses in neural cells. Conversely,…
A novel type of photonic crystal formed by embedding a periodic array of constituent stacks of alternating graphene and dielectric discs into a background dielectric medium is proposed. The photonic band structure and transmittance of such…
We investigate the topological phase transitions in graphene under the modulation of circularly polarized light, by analyzing the changes of edge states and its topological structures. A full phase diagram, with up to ten different…
Chirality arises from the asymmetry of matters, where two counterparts are the mirror image of each other. The interaction between circular-polarization light and quantum materials is enhanced in chiral space groups due to the structural…