Figure 3: Weyl points in a time-reversal symmetry breaking structure.
From: Photonic Weyl point in a two-dimensional resonator lattice with a synthetic frequency dimension
(a) Modulation phase ϕA=+π/3 and ϕB=−π/3 leads to time-reversal symmetry breaking. (b) The Weyl points in the reciprocal space, and their charges. The Weyl points are located at ky=0, 
and kf=0 or 
. (c) The band structure in kx−kf plane at ky=0. The Weyl points at 
are equivalent to those at 
in b. (d) The band structure in ky−kf plane at 
. The charge of each Weyl point is shown underneath.
