FARAH RASHEEDCIIT/SP19-RPH-014/LHRDr. Faheel Ather HashmiLHR TP 72342026-02-152021https://repository.cuilahore.edu.pk/handle/123456789/1632In this thesis we reproduce the results claimed in the article PRL 117, 043601 (2016) titled “One Photon Can Simultaneously Excite Two or More Atoms”. The claim is very counter-intuitive and needs proper understanding. We present our understanding in this work. The work deals with ultra strong light matter interaction and superconductor quantum circuits. We review these in the thesis and justify the Hamiltonian given in the paper. We next numerically diagonalize the Hamiltonian to reproduce the eigenvalues plotted in the paper. There is a little discrepancy in the corresponding eigenvectors reported in the paper and in our work. Future work on the project can resolve the discrepancy. Finally, we work out the time evolution equations of the system.enDepartment of PhysicsSP19PhysicsStrong Coupling RegimePhotonAtomsThesis