# Control over few photon pulses by a time-periodic modulation of the photon-emitter coupling

## TL;DR

This paper introduces a Floquet scattering formalism to control microwave photon pulses in a waveguide with a periodically modulated nonlinear cavity, enabling phenomena like photon blockade and compression through non-adiabatic effects.

## Contribution

It presents a novel Floquet scattering approach for analyzing quasistationary photon states with time-periodic coupling, inspired by superconducting qubit technology.

## Key findings

- Periodic modulation causes strong transmission and reflection variations.
- Photon blockade and compression are achieved via non-adiabatic effects.
- The model explains complex photon statistics changes.

## Abstract

We develop a Floquet scattering formalism for the description of quasistationary states of microwave photons in a one-dimensional waveguide interacting with a nonlinear cavity by means of a periodically modulated coupling. This model is inspired by the recent progress in engineering of tunable coupling schemes with superconducting qubits. We argue that our model can realize the quantum analogue of an optical chopper. We find strong periodic modulations of the transmission and reflection envelopes in the scattered few-photon pulses, including photon compression and blockade, as well as dramatic changes in statistics. Our theoretical analysis allows us to explain these non-trivial phenomena as arising from non-adiabatic memory effects.