We consider the open Jaynes-Cummings model driven on the two{photon resonance, in the regime of very strong coupling. The open nature of the system means that loss of photons through the cavity mirrors as well as through spontaneous emission is allowed for. A variety of interesting quantum{optical phenomena have already been found to occur in this system. Specifically, behaviour indicative of a multiphoton blockade has been observed, and the system undergoes a transition from strongly bunched to antibunched light production as the drive strength is increased. In this thesis, we examine the possibility of finding squeezed light in the cavity output field, through numerical simulations and an analytic model of the system. For this purpose, calculations exploring squeezing of the cavity internal mode in the system steady{state are performed, and the squeezing spectrum of the cavity output field is computed. In addition to the two{photon resonance, the Jaynes-Cummings model with the atom, cavity mode and external drive all resonant is considered. The quasienergies and quasienergy states for this system are known, and exhibit interesting behaviour with regards to squeezing as a certain critical point in the drive strength is approached. We explore the possibility of performing an adiabatic following of the system ground state in order to obtain squeezing of the cavity internal mode, both in the presence and absence of damping.

The subject of this book is the new field of squeezing in quantum fields. This general area includes all types of systems in which quantum fluctuations are reduced below those in the normal vacuum state. The book covers the main currently known techniques of generating squeezed photon fields, together with some treatment of matter field squeezing. Both theory and experiments are covered, together with applications to communications and measurement. The chapters of the book are written by the foremost international experts in the field, and their coverage extends from general introductory material, to the most recent developments.

"We present a generic cavity quantum electrodynamics (QED) set-up that can generate different types of strong multipartite entanglement. The proposed system is already accessible at the experimental level in different cavity QED architectures as it only involves a spin ensemble weakly coupled to a two-photon driven cavity. The first entangling scheme we propose, the dark-mode assisted protocol (DMAP), consists in transferring the squeezing from the cavity to the spin ensemble. The resulting spin squeezed state (with a Kitawaga spin squeezing parameter on the order of 10−2) has strong pairwise entanglement that is especially useful for quantum metrology. In a relatively short timescale (inversely proportional to the collective coupling strength), our scheme can almost reach the quantum Heisenberg limit (with a Wineland spin squeezing parameter close to 2/N), even for a few spins. Unlike one-axis twisting and two-axis countertwisting, the amount of spin squeezing generated by our scheme is not constrained by the number of spins. Our scheme is faster and doesn't suffer the oscillatory dynamics of one-axis twisting. We will also demonstrate how the DMAP can be analyzed as an adiabatic evolution even though achieving adiabaticity might seem impossible in our gapless system. In the second part of the thesis, we build on our previous work which showed that a two-photon drive can be used to simulate ultra-strong coupling in a standard cavity QED system where the cavity is weakly coupled to a single qubit. We extend this approach to a cavity weakly interacting with a spin ensemble and simulate the Dicke model, which is known to exhibit interesting quantum features such as strong entanglement and quantum phase transitions. The other entangling schemes we propose, make use of the simulated Dicke model: the realization of a Molmer-Sorenson gate, closely related to one-axis twisting, and the generation of large multipartite entangled cat-states. We demonstrate how our scheme can be used to prepare a remote entanglement protocol, a key ingredient in quantum information, where the weakly interacting Hamiltonian is used to grow a Greenberger-Horne-Zeilinger state which will then be transformed into an entangled-cat state by the simulated Dicke Hamiltonian. Finally we illustrate how our system can become an interesting platform to study superradiant phase transition and as well as the effects of squeezed input noise." --

What happens to light when it is trapped in a box? Cavity Quantum Electrodynamics addresses a fascinating question inphysics: what happens to light, and in particular to itsinteraction with matter, when it is trapped inside a box? With theaid of a model-building approach, readers discover the answer tothis question and come to appreciate its important applications incomputing, cryptography, quantum teleportation, andopto-electronics. Instead of taking a traditional approach thatrequires readers to first master a series of seemingly unconnectedmathematical techniques, this book engages the readers' interestand imagination by going straight to the point, introducing themathematics along the way as needed. Appendices are provided forthe additional mathematical theory. Researchers, scientists, and students of modern physics can referto Cavity Quantum Electrodynamics and examine the field thoroughly.Several key topics covered that readers cannot find in any otherquantum optics book include: * Introduction to the problem of the "vacuum catastrophe" and thecosmological constant * Detailed up-to-date account of cavity QED lasers andthresholdless lasing * Examination of cavities with movable walls * First-principles discussion about cavity QED in opencavities * Pedagogical account of microscopic quantization indielectrics Complementing the coverage of the most advanced theory andtechniques, the author provides context by discussing thehistorical evolution of the field and its discoveries. In thatspirit, "recommended reading," provided in each chapter, leadsreaders to both contemporary literature as well as key historicalpapers. Despite being one of many specialties within physics, cavityquantum electrodynamics serves as a window to many of thefundamental issues of physics. Cavity Quantum Electrodynamics willserve as an excellent resource for advanced undergraduate quantummechanics courses as well as for graduate students, researchers,and scientists who need a comprehensive introduction to the field.