Related papers: Photon-number selective group delay in cavity indu…
A novel method of preparing a single photon in temporally-delocalized entangled modes is proposed and analyzed. We show that two single-photon pulses propagating in a driven nonabsorbing medium with different group velocities are temporally…
Quantum coherent control of slow light for all-optical switching is investigated in a multi-level system of solids for an understanding of self-induced ultraslow light. In an optical population shelving system of a rare-earth doped solid,…
We study the collective emission of a beam of atomic dipoles into an optical cavity. Our focus lies on the effect of a finite detuning between the atomic transition frequency and the cavity resonance frequency. By developing a theoretical…
The interaction between photons and a single two-level atom constitutes a fundamental paradigm in quantum physics. The nonlinearity provided by the atom means that the light-matter interaction depends strongly on the number of photons…
Photonic entanglement has a wide range of applications in quantum computation and communication. Here we introduce a new device: the "photonic module", which allows for the rapid, deterministic preparation of a large class of entangled…
In this article, we propose a method to realize the "delayed choice experiment" using ultra-cold atoms. Here we attempt to probe the "welcher-Weg" information without collapsing the wavefunction of the atom. This experiment consists of…
The quantum dynamics of a system of Rb atoms, modeled by a V-type three-level system interacting with intense probe and pump pulses, are studied. The time-delay-dependent transient-absorption spectrum of an intense probe pulse is thus…
We present a novel method for quantum tomography of multi-qubit states. We apply the method to spin-multi-photon states, which we produce by periodic excitation of a semiconductor quantum-dot- confined spin every 1/4 of its coherent…
Entangled photons have the remarkable ability to be more sensitive to signal and less sensitive to noise than classical light. Joint photons can sample an object collectively, resulting in faster phase accumulation and higher spatial…
We theoretically propose a scheme for photon blockade in a cavity quantum electrodynamical system consisting of an N-type atomic medium interacting with a single-mode Fabry-Perot cavity. In contrast to inefficient…
We investigate atom-photon entangling gates based on cavity quantum electrodynamics (QED) for a finite photon-pulse duration, where not only the photon loss but also the temporal mode-mismatch of the photon pulse becomes a severe source of…
The transient-absorption spectrum of a $V$-type three-level system is investigated, when this is periodically excited by a train of equally spaced, $\delta$-like pump pulses as, e.g., from an optical-frequency-comb laser. We show that, even…
Deterministic optical quantum logic requires a nonlinear quantum process that alters the phase of a quantum optical state by $\pi$ through interaction with only one photon. Here, we demonstrate a large conditional cross-phase modulation…
A source of deterministic single photons is proposed and demonstrated by the application of a measurement-based feedback protocol to a heralded single photon source consisting of an ensemble of cold rubidium atoms. Our source is stationary…
By projecting onto complex optical mode profiles, it is possible to estimate arbitrarily small separations between objects with quantum-limited precision, free of uncertainty arising from overlapping intensity profiles. Here we extend these…
We show that a pair of quantized cavity modes interacting with a spectrally broadened ensemble of Lambda-type atoms is analogous to an ensemble of two level systems coupled to a bosonic reservoir. This provides the possibility for an…
We extend the theory to describe the quantum light memory in type atoms with considering (lower levels coherency decay rate) and detuning for the probe and the control fields. We obtain that with considering these parameters, group velocity…
Between mirrors, the density of electromagnetic modes differs from the one in free space. This changes the radiation properties of an atom as well as the light forces acting on an atom. It has profound consequences in the strong-coupling…
Over the last decades, quantum optics has evolved from high quality factor cavities in the early experiments toward new cavity designs involving leaky modes. Despite very reliable models, in the concepts of cavity quantum electrodynamics,…
We experimentally study the interaction between a cold atom cloud and many longitudinal modes of a high quality Fabry-Perot cavity, by measuring signatures of collective light shifts in the cavity transmission spectrum of an optical…