High temperature superradiant phase transition in novel quantum structures with complex network interface

Abstract: In the present work we propose a novel quantum material concept, which enables super- and/or ultrastrong interaction of two-level systems with the photonic field in a complex network. Within the mean field approximation we examine phase transition to superradiance that results in two excitation (polariton) branches and is accompanied by the appearance of non-zero macroscopic polarization of two-level systems. We characterize the statistical properties of networks by the first, ${\langle}k{\rangle}$, and second normalized, $\zeta\equiv{\langle}k^2{\rangle}/{\langle}k{\rangle}$, moments for node degree distribution. We have shown that the Rabi frequency is essentially enhanced due to the topology of the network within the anomalous domain where ${\langle}k{\rangle}$ and $\zeta$ sufficiently grow. The multichannel (multimode) structure of matter-field interaction leads superstrong coupling that provides primary behavior of the high temperature phase transition. The results obtained pave the way to design new photonic and polaritonic circuits, quantum networks for efficient processing quantum information at high (room) temperatures.