Fig. 3: Observation of massive non-Hermitian Dirac quasiparticles.
From: Non-Hermitian Dirac cones with valley-dependent lifetimes
a Calculated bulk dispersion of the circuit lattice with parameters Ca = 100 nF, Cb = 200 nF, C = 100 nF, C1 = C2 = 10 nF, L = 1.043 μH and Rs = 30 Ω. The colors denote the imaginary part of the eigenfrequencies. b, c Experimentally measured dispersions of the circuit lattice along high-symmetry lines when exciting at the sublattice A (b) and the sublattice B (c), respectively. The colors represent the normalized Fourier intensity, and the dashed lines represent the theoretical results. d Experimentally measured dispersion of the circuit lattice in the two-dimensional momentum space. The measurements are taken at 222 kHz (upper panel) and 200 kHz (lower panel) with excitations at the sublattices A and B, respectively. e Measured voltage amplitudes at 222 kHz (left panel) and 200 kHz (right panel) with excitations at the sublattices A and B, respectively. The black star denotes the source. Zoomed-in bar diagrams plot the amplitudes (heights) and phases (colors) distribution in a hexagonal cell and demonstrate the clockwise and anti-clockwise phase vortices at sublattices A (lower panel) and B (upper panel).
