▎ 摘　　要

Using the transfer matrix in the angular-momentum space we investigate the impact of trigonal warping on magnetotransport and scaling properties of a ballistic bilayer graphene in the Corbino geometry. Although the conductivity at the charge-neutrality point and zero magnetic field exhibits a one-parameter scaling, the shot-noise characteristics, quantified by the Fano factor F and the third charge-transfer cumulant R, remain pseudodiffusive. This shows that the pseudodiffusive transport regime in bilayer graphene is not related to the universal value of the conductivity but can be identified by higher charge-transfer cumulants. For Corbino disks with larger radii ratios, the conductivity is suppressed by the trigonal warping, mainly because the symmetry reduction amplifies backscattering for normal modes corresponding to angular-momentum eigenvalues +/- 2h. Weak magnetic fields enhance the conductivity, reaching the maximal value near the crossover field B-L = 4/3 root 3 (h/e)t't(perpendicular to)[t(0)(2)a(R-o-R-i)](-1), where t(0) (t(perpendicular to)) is the nearest-neighbor intralayer (interlayer) hopping integral, t' is the skew-interlayer hopping integral, and R-o (R-i) is the outer (inner) disk radius. For magnetic fields B greater than or similar to B-L we observe quasiperiodic conductance oscillations characterized by the decreasing mean value - sigma(0) proportional to B-L/B, where sigma(0) = (8/pi) e(2)/h. The conductivity, as well as higher charge-transfer cumulants, show beating patterns with an envelope period proportional to root B/B-L. This constitutes a qualitative difference between the high-field (B >> B-L) magnetotransport in the t' = 0 case [earlier discussed in Rut and Rycerz, J. Phys.: Condens. Matter 26, 485301 (2014)] and in the t' not equal 0 case, providing a finite-system analog of the Lifshitz transition.