Study On Nonreciprocal Nonconventional Photon Blockade In Second-order Nonlinear Coupled Cavity System

As an important phenomenon in nonlinear optics,second-order nonlinear effect has been one of the research hotspots of quantum information and quantum optics since its birth due to its potential application prospect.In recent years,the preparation and manipulation of single photon source is very important in the field of quantum information and quantum communication,and it has great significance in theory,experimental research and application.With the rapid development of coupled cavity system in theory and experiment,quantum phenomena and optical effects have more extensive research prospects,especially in the second-order nonlinear effect,we can use photon blockade mechanism to realize single photon source.Nonreciprocal optical devices allow the incident light to have different characteristics in different propagation directions,and also play a very important role in signal processing and invisible light sensing applications.Therefore,it is worthy of further exploration to combine the photon blockade effect caused by second-order nonlinearity with nonreciprocity in the field of quantum devices.In this paper,the nonreciprocal unconventional photon blockade effect in a two cavity rotating system with second-order nonlinearity is studied.It is found that the strong photon antibunching can only be generated by the laser driving system from the left side instead of the right side in the rotating nonlinear optical cavity,so the unconventional photon blockade can be generated by the nonreciprocity,which is caused by the different splitting of resonance frequency in the optical counting cycle mode caused by the Fizeau drag.At the same time,it can be found that the nonreciprocal unconventional photon blockade is caused by the destructive quantum interference between different paths,and the optimal condition of strong photon antibunching is derived analytically,which is consistent with the results of numerical simulation.In the case of weak driving,we prove that the nonreciprocal unconventional photon blockade effect can not be observed by calculating the second-order correlation function,which is due to the system can not form two closed quantum channels.The relative phase of the two external fields can also be used to control the photon blockade,and the tunable nonreciprocal unconventional photon blockade effect can be obtained by adjusting the angular velocity.Finally,we give the analytic solution of the delayed second-order correlation function and verify the experimental data.