The Study Of Transmission Characteristics Of Whispering-gallery-mode Microresonator Embedded In Two Atoms With Dipole-dipole Interaction

With the continuous attention of modern science and technology to quantum information technology,more and more people pay attention to the operation and regulation of micro quantum state.Photon,as a neutral particle,has no direct interaction with the environment,and has the advantages of fast speed and strong anti-interference ability.Therefore,it has become an ideal carrier of quantum information.Most models manipulate single photons by controlling the interaction between the cavity and the atom so as to achieve the controlled transmission of single photons.Aoki et al.achieved efficient routing of single photons using an atom and a microresonator.But when two atoms are coupled into the same cavity,the interaction becomes more complex and more physical mechanisms need to be considered.The dipole-dipole interaction between the two atoms plays an important role in the state evolution of the system.When the distance between two atoms is much smaller than the resonant wavelength,the dipole-dipole interaction cannot be ignored.In addition,the development of high precision manipulation of atoms and high quality microcavity technology provides the possibility of future research on dipole-dipole interaction.It has been known from previous studies that photon transmission can be controlled by adjusting coupling strength,photon-atom detuning,or classical driving field.However,as far as we know,the effect of dipole-dipole interaction on photon transmission in whispering-gallery-mode microresonator has not been considered theoretically before,and it is of great value to study.In this paper,we first construct the Hamiltonian,then use the method of master equation,combine with the input-output theory,deduce the transmission spectrum and reflection spectrum of the system in detail,and analyze the influence of dipole-dipole interaction on the photon transport.The results show that the dipole-dipole interaction can regulate the transmittance and reflectivity,and the intensity of the dipole-dipole interaction can be determined by the transmission and reflection spectra in turn.The transmission spectrum in the corridor mode cavity is usually symmetric Lorentz line,but in our system,the spectrum lines are sharp,obviously asymmetric and the bandwidth is very small,which is the standard Fano line.The asymmetrical Fano profile is steeper and has a much higher slope than the Lorentz profile,and the transmittance varies greatly over a small frequency range.Based on this feature,we can design optical switches with high contrast,low pump power and faster response time.Moreover,as the intensity of the dipole-dipole interaction increases,the form of the Fano line remains the same,which is caused by the interaction of the dipole-dipole interaction and other system parameters.However,in practice,it is necessary to consider the influence of the dissipation effect,which reduces the efficiency of the quantum switch.Fortunately,the competition between system parameters such as the coupling strength between atoms and cavity modes and the coupling strength between cavity modes and the dipole-dipole interaction can make the range of transmittance and reflectance larger and reduce attenuation.The resulting impact provides more possibilities for the regulation of single photon transport.