Radio-frequency communication systems have long used bulk-and surface-acoustic-wave
devices supporting ultrasonic mechanical waves to manipulate and sense signals. These …

We present a fully passive method for implementing a quantum phase gate between two
photons traveling in a one-dimensional waveguide. The gate is based on chirally coupled …

A cross-Kerr interaction produces a phase shift on two modes of light proportional to the
number of photons in both modes and is sometimes called cross-phase modulation. Cross …

A central goal of quantum optics is to generate large interactions between single photons so
that one photon can strongly modify the state of another one. In cavity optomechanics …

We present an improved version of the superatom (SA) model to examine the slow-light
dynamics of a few-photons signal field in cold Rydberg atoms with van der Waals (vdW) …

It has been suggested that second-order nonlinearities could be used for quantum logic at
the single-photon level. Specifically, successive two-photon processes in principle could …

A second-order nonlinearity has been proposed as a way to perform a conditional phase
gate between two photons. The process involves combining the two photons into a single …

We apply the method of the resolvent of Hamiltonian to investigate the mechanical cooling
behavior in the single-photon optomechanical regime. This approach allows for a direct …

Recent experimental progress has realized strong, efficient coupling of effective two level
systems to waveguides. We study the scattering of multimode photons from such emitters …

In this dissertation, we shall focus on theoretically studying quantum nonlinear optical
schemes to construct a conditional phase gate at the single-photon level. With an aim to …