▎ 摘　　要

We model the magnetic ratchet effect in bilayer graphene in which a dc electric current is produced by an ac electric field of frequency. in the presence of a steady in-plane magnetic field and inversion-symmetry breaking. In bilayer graphene, the ratchet effect is tunable by an external metallic gate which breaks inversion symmetry. For zero in-plane magnetic field, we show that trigonal warping and inversion-symmetry breaking are able to produce a large dc valley current, but not a nonzero total dc charge current. For the magnetic ratchet in a tilted magnetic field, the perpendicular field component induces cyclotron motion with frequency omega(c) and we find that the dc current displays cyclotron resonance at omega(c) = omega, although this peak in the current is actually smaller than its value at omega(c) = 0. Second harmonic generation, however, is greatly enhanced by resonances at omega(c) = omega and omega(c) = 2 omega for which the current is generally much larger than at omega(c) = 0.