Fig. 5: Suppressed inter-valley scattering at the armchair interface.
From: Non-Hermitian Dirac cones with valley-dependent lifetimes
a Plots of the real (blue dots) and imaginary (red dots) parts of the valley kink states' eigenfrequencies at ky = 0 of a heterostructure with an armchair interface against the ratio between the nonreciprocal part C2 and the reciprocal part C1 of the NNN coupling. The blue and red regions denote the parity-time symmetric and parity-time symmetry-broken phases, respectively. b, c Calculated dispersions for the two cases denoted by the black stars in (a) (C2/C1 = 0.1 for (b) and C2/C1 = 1 for (c)). The colors denote the imaginary part of the eigenfrequencies. Circuit parameters are C = 100 nF, C1 = 10 nF, L = 1.043 μH, and Rs = 30 Ω. d, e Experimentally measured edge dispersions from Fourier transform of the fields at the interface with excitations at the bottom (d) and top (e) sides, respectively. The colors represent the normalized Fourier intensity and the dashed lines represent the theoretical results. f Measured voltage field distributions at 215 kHz with excitations at the bottom (left panel) and top (right panel). The black star denotes the source and the dashed lines mark the location of the armchair interface.
