After obtaining my masters in physics, I joined CUSAT as a project fellow under the KSCSTE emeritus scientist scheme, with Dr. Ramesh Babu T. In collaboration with his PhD student Muhammed Ashefas we produced three three research papers. Following are the link and abstract to them.
Kerr-Nonlinearity Enhanced Single Photon Blockade in Jaynes-Cummings Model
Abstract: We present a theoretical investigation of the single photon blockade effect in a driven qubit-cavity system with Kerr nonlinearity and dissipation. External fields drive both the cavity field and qubit. We calculated the equal time photon correlation functions and photon number distributions for different parameter domains of the system, including qubit-cavity detuning and found an enhancement of single photon blockade with Kerr nonlinearity irrespective of the domains. We propose a new measure for verifying single photon blockade in terms of correlation functions, and it is consistent with the criteria for photon blockade. The proposed scheme is more effective for the experimental realization of single photon sources using a qubit-cavity system.
Preservation of dynamics in coupled cavity system using second order nonlinearity
Abstract: We study two coupled cavities with a single two-level system in each and a second-order non-linear process in one of the cavities. Introduction of a harmonic time dependence on the non-linear coupling is utilized for the preservation of dynamics. It is observed that, even though the preservation period is independent of the initial state, the preserved dynamics depends on the initial state. We calculated the von Neumann entropy and mutual information to study the entanglement present between the subsystems. From which it is found that the time-dependent coupling also preserves the entanglement produced in the system.
Effects of Kerr medium in coupled cavities on quantum state transfer
Abstract: We study the effect of Kerr type nonlinear medium in quantum state transfer (QST). We have investigated the effect of different coupling schemes and Kerr medium parameters \(p\) and \(\omega_k\). We found that the Kerr medium introduced in the connection channel can act like a controller for QST. The numerical simulations are performed without taking the adiabatic approximation. Rotating wave approximation is used in the atom–cavity interaction only in the lower coupling regime.