Fig. 7: Gain and reverse gain.
From: Topological framework for directional amplification in driven-dissipative cavity arrays
In (b) we show the gain \({\mathcal{G}}(\omega )\) of Eq. (48) (solid line) and reverse gain \(\overline{{\mathcal{G}}}(\omega )\) of Eq. (49) (dashed line) for \({\mathcal{C}}=1.5\) for different θ. The gain is a product of Lorentzians of width (γ + 2Γ − κ), cf. Eq. (51). The position of the divergences at larger \({\mathcal{C}}\) in a sets the position of the peak in gain and reverse gain. For \(\theta =\frac{\pi }{2},\frac{3\pi }{2}\) the peak is centered around ω = 0.
