# On-Chip Photonic Transistor based on the Spike Synchronization in Circuit QED

## TL;DR

This paper explores a single photon transistor using coupled resonator cavities and multilevel superconducting atoms, analyzing photon interactions, blockade, and synchronization phenomena in circuit QED systems.

## Contribution

It introduces a novel on-chip photonic transistor design based on spike synchronization in circuit QED with detailed analysis of photon blockade and cavity field dynamics.

## Key findings

- Demonstrates photon blockade and localization-delocalization transitions.
- Shows synchronization of spike trains with cavity field population imbalance.
- Achieves gain enhancement with a single photon gate field.

## Abstract

We consider the single photon transistor in coupled cavity system of resonators interacting with multilevel superconducting artificial atom simultaneously. Effective single mode transformation is used for the diagonalization of the the hamiltonian and impedance matching in terms of the normal modes. Storage and transmission of the incident field are described by the interactions between the cavities controlling the atomic transitions of lowest lying states. Rabi splitting of vacuum induced multiphoton transitions is considered in input/output relations by the quadrature operators in the absence of the input field. Second order coherence functions are employed to investigate the photon blockade and localization-delocalization transitions of cavity fields in oscillating regime of photon states described by the the population imbalance. Refection and transmission of cavity output fields are investigated in the presence of the multilevel transitions. Accumulation and firing of the reflected and transmitted fields are used to investigate the synchronization of the bunching spike train of transmitted field and population imbalance of cavity fields. In the presence of single photon gate field, gain enhancement is explained for transmitted regime.