相关论文: Tuning anti-Klein to Klein tunneling in bilayer gr…

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…

We review chiral (Klein) tunneling in single-layer and bilayer graphene and present its semiclassical theory, including the Berry phase and the Maslov index. Peculiarities of the chiral tunneling are naturally explained in terms of…

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…

When a gap of tunable size opens at the conic band intersections of graphene, the Berry phase does not vanish abruptly, but progressively decreases as the gap increases. The phase depends on the reciprocal-space path radius, i.e., for a…

Ever since the novel quantum Hall effect in bilayer graphene was discovered, and explained by a Berry phase of 2pi [K. S. Novoselov et al., "Unconventional quantum Hall effect and Berry's phase of 2pi in bilayer graphene", Nature Phys. 2,…

The electronic dispersion of a graphene bilayer is highly dependent on rotational mismatch between layers and can be further manipulated by electrical gating. This allows for an unprecedented control over electronic properties and opens up…

Chiral quasiparticles in Bernal-stacked bilayer graphene have valley-contrasting Berry phases of 2{\pi}. This nontrival topological structure, associated with the pseudospin winding along a closed Fermi surface, is responsible for various…

We report the experimental observation of Fabry-P\'erot (FP) interference in the conductance of a gate-defined cavity in a dual-gated bilayer graphene (BLG) device. The high quality of the BLG flake, combined with the device's electrical…

Recent experiments have measured local uniaxial strain fields in twisted bilayer graphene (TBG). Our calculations found that the finite Berry curvature generated by breaking the sublattice symmetry and the band proximity between narrow…

We have utilized the finite-difference approach to explore electron-tunneling properties in gapped graphene through various electrostatic-potential barriers changing from Gaussian to a triangular envelope function in comparison with a…

Berry phase plays an important role in determining many physical properties of quantum systems. However, a Berry phase altering energy spectrum of a quantum system is comparatively rare. Here, we report an unusual tunable valley polarized…

We have found that the Berry phase of bilayer graphene becomes from 2$\pi$ estimated by Shubnikov-de Haas oscillations when the A-B stacked pristine bilayer graphene experiences the Li-intercalation and sequential Li-desorption process in…

The paper discusses the Klein tunneling and Fabry-P\'erot resonances of charge carriers through a rectangular potential barrier in twisted bilayer graphene. Within the framework of the low-energy excitations, the transmission probability…

The conductance through single-layer graphene (SLG) and AA/AB-stacked bilayer graphene (BLG) junctions is obtained by taking into account band gap and bias voltage terms. First, we consider gapped SLG, while in between, they are connected…

Bilayer graphene -- two coupled single graphene layers stacked as in graphite -- provides the only known semiconductor with a gap that can be tuned externally through electric field effect. Here we use a tight binding approach to study how…

Since its discovery, Berry phase has been demonstrated to play an important role in many quantum systems. In gapped Bernal bilayer graphene, the Berry phase can be continuously tuned from zero to 2pi, which offers a unique opportunity to…

The perfect transmission in graphene monolayer and the perfect reflection in Bernal graphene bilayer for electrons incident in the normal direction of a potential barrier are viewed as two incarnations of the Klein paradox. Here we show a…

Exact conditions for anti-Klein transmission zeros are found analytically with a 4-component continuum approach which includes trigonal warping. Anti-Klein tunneling occurs at oblique incidence on steps and barriers with soft and hard walls…

We calculate the transmission coefficient for a particle crossing a potential barrier in monolayer graphene with Rashba spin-orbit coupling and in bilayer graphene. We show that in both the cases one can go from Klein tunneling regime,…

One of the unique features of graphene is that the Fermi wavelength of its charge carriers can be tuned electrostatically over a wide range. This allows in principle to tune the transparency of a pn-junction electrostatically, as this…