Fig. 3: Evidence of P2 SSB.
From: Nonlinear topological symmetry protection in a dissipative system
Oscilloscope recordings of the intensity of the a + and b − hybrid modes and c total intensity over 20 subsequent resonator roundtrips (X = 50, Δ = 10). The alternation of the hybrid mode intensities is a key signature of the underlying Möbius topology while the constant total intensity indicates a high level of symmetry between the hybrid modes. d High and low-intensity levels of the + (blue) and − (orange) hybrid modes versus resonator detuning, revealing a pitchfork bifurcation (X = 50). The black lines are numerical predictions (dashed lines correspond to unstable states). e Complex plane showing the real (in-phase, I) and imaginary (quadrature, Q) components of \({\psi }_{x}{\psi }_{y}^{*}\) measured over 1000 resonator roundtrips in the P2 SSB regime. Cyan and purple density plots correspond, respectively, to odd and even roundtrips, and their diametrically opposite placement signals that the relative phase between the x and y fields changes by π at every roundtrip. The spread of each density is magnified four times for clarity.
