One of most important conclusions in cavity-quantum-electrodynamics is that spontaneous emission of an atom can be controlled by squeezing zero-point fluctuations of the photon fields surrounding the atom in both spatial and frequency domains1). As for quantum optoelectronic device application, in addition to quantum control of photon system, it is of great important to dynamically control electron system as well in order to alter spontaneous emissions. This can be easily realized in semiconductor systems by a combined use of distributed Bragg reflectors (DBRs) and the quantum confined Stark effect (QCSE) for control of photon and electron systems, respectively. The main purpose of this talk is to demonstrate our experimental results on physical phenomena originating from quantum control of electron-and photon-systems2)3), and its implications for device-applications4) involving the possibility of a novel scheme for the generation of photon-number squeezed state5).
One of most important conclusions in cavity-quantum-electrodynamics is that spontaneous emission of an atom can be controlled by squeezing zero-point fluctuations of the photon fields surrounding the atom in both spatial and frequency domains1). As for quantum optoelectronic device application, in addition to quantum control of photon system, it is of great important to dynamically control electron system as well in order to alter spontaneous emissions. This can be easily realized in semiconductor systems by a combined use of distributed Bragg reflectors (DBRs) and the quantum confined Stark effect (QCSE) for control of photon and electron systems, respectively. The main purpose of this talk is to demonstrate our experimental results on physical phenomena originating from quantum control of electron-and photon-systems2)3), and its implications for device-applications4) involving the possibility of a novel scheme for the generation of photon-number squeezed state5).
One of most attractive discoveries in cavity-quantum-electrodynamics in a past decade is that spontaneous emission of an atom can be controlled by squeezing zero-point fluctuations of the photon fields surrounding the atom in both spatial and frequency domains1). Considering quantum optoelectronic device-applications, in addition to control of photon system, it is of great important to control electron system as well in order to alter spontaneous emissions. This can be easily realized, by up-date technologies, in semiconductor systems by use of distributed Bragg reflectors (DBRs) and the quantum confined Stark effect (QCSE) for control of photon and electron systems, respectively. The main purpose of this paper is to review our experimental results on physical phenomena originating from control of quantum electron- and photon-systems2), and its possible device-applications
Though QD arrays have initially been mostly studied in an attempt to improve semiconductor lasers, much attention has been recently devoted to the revolutionary prospects opened by the unique properties of single QDs. These artificial atoms allow to mimic in solid-state systems some of the quantum optics experiments performed on atoms since the early 80’s. Recent demonstrations of coherent control experiments on QDs illustrate this fruitful analogy [10]. We will focus here our discussion on the impact of QDs on two other fields, solid-state cavity quantum electrodynamics (CQED) and the generation of quantum states of light. A single QD can be used to emit triggered single photon pulses and photon pairs, whereas its narrow emission spectrum permits to implement microcavities very efficiently to tailor its emission properties. By combining both kind of effects, it is possible to control simultaneously the number of emitted photons as well as their quantum state and to build a solid-state singlemode source of single photons (singlemode S4P) as proposed [11] and demonstrated recently by our group [12]. This novel device represents the ultimate step in a field which has been extremely active in the last 15 years, spontaneous emission (SE) control in optoelectronic devices using confined electronic and/or photonic systems [13]. Before reviewing the development of this single mode S4P, based on a single QD in a pillar microcavity, we will briefly discuss its potential applications in the field of quantum information processing and quantum communications (QIPC).
Abstract : Spontaneous emission of an atom is not an immutable property of an atom but can be controlled by modification of the vacuum field fluctuations surrounding the atom. In fact, inhibition and enhancement of spontaneous emission of atoms both at microwave and optical frequencies have been demonstrated experimentally. It has, also, been demonstrated that spontaneous emission from GaAs quantum wells (QWs) is altered by embedding the QWs between AlAs/AlGaAs distributed Bragg reflectors (DBRs). Such an artificial modification of the spontaneous emission in semiconductor micro-structures is very important, particularly from device use point of view. We may, also expect enhancement and inhibition of spontaneous emission induced by tuning of emission wavelength of atoms or active materials embedded in fixed micro-cavities, instead of variation of micro-cavity structures. In this paper, we demonstrate, for the first time, controllable enhancement and inhibition of excitonic spontaneous emission by dc electric fields applied to a GaAs QW embedded in a pair of AlAs/AlGaAs DBRs.
This focused review discusses the increasing importance of quantum optics in the physics and engineering of optoelectronic components. Two influences relating to cavity quantum electrodynamics are presented. One involves the development of low threshold lasers, when the channeling of spontaneous emission into the lasing mode becomes so efficient that the concept of lasing needs revisiting. The second involves the quieting of photon statistics to produce single-photon sources for applications such as quantum information processing. An experimental platform, consisting of quantum-dot gain media inside micro- and nanocavities, is used to illustrate these influences of the quantum mechanical aspect of radiation. An overview is also given on cavity quantum electrodynamics models that may be applied to analyze experiments or design devices.
Superradiance is one of the many fascinating phenomena predicted by quantum electrodynamics that have first been experimentally demonstrated in atomic systems and more recently in condensed matter systems like quantum dots, superconducting q-bits, cyclotron transitions and plasma oscillations in quantum wells (QWs). It occurs when a dense collection of N identical two-level emitters are phased via the exchange of photons, giving rise to enhanced light-matter interaction, hence to a faster emission rate. Of great interest is the regime where the ensemble interacts with one photon only and therefore all of the atoms, but one, are in the ground state. In this case the quantum superposition of all possible configurations produces a symmetric state that decays radiatively with a rate N times larger than that of the individual oscillators. This phenomenon, called single photon superradiance, results from the exchange of real photons among the N emitters. Yet, to single photon superradiance is also associated another collective effect that renormalizes the emission frequency, known as cooperative Lamb shift. In this work, we show that single photon superradiance and cooperative Lamb shift can be engineered in a semiconductor device by coupling spatially separated plasma resonances arising from the collective motion of confined electrons in QWs. These resonances hold a giant dipole along the growth direction z and have no mutual Coulomb coupling. They thus behave as a collection of macro-atoms on different positions along the z axis. Our device is therefore a test bench to simulate the low excitation regime of quantum electrodynamics.
In this paper, exciting progress of quantum optics in solid state is reviewed. The focus is on semiconductor microcavities with self-assembled quantum dots embedded in the active layer. Due to enormous progress in semiconductor nanotechnology, such photonic structures have become a model system for the study of quantum optics on a scalable and integrable technology platform with high potential for future applications in quantum information technology. Quantum optical phenomena have become accessible due to 3-D confinement of light and matter on the length scale of their wavelength in state-of-the-art semiconductor micro- and nanostructures. This confinement leads to a quantization of the associated photonic and electronic energy levels and requires a quantum mechanical description of the system in the framework of cavity quantum electrodynamics (cQED). This approach considers the dipole interaction between two-level quantum emitters and discrete photonic states of a microcavity. Within the well-known Jaynes-Cummings model, the dipole interaction is described in terms of a coherent exchange of energy between the emitter and the resonator mode. This coherent interaction in the so-called strong coupling regime of cQED is reflected in a normal mode splitting, the vacuum Rabi splitting, of the involved modes and represents a central feature of quantum optics in solid state. Another important example of quantum optics in semiconductor nanostructures is the generation of nonclassical light in specific quantum devices. Of particular interest is the realization of Fock states which represent states containing a well-defined number of photons. Single-photon sources, for instance, allow for the generation of single photons on demand, which is highly desirable for quantum communication systems. In this context, this review paper will present recent experimental studies of quantum optics in solid state. This paper is meant for readers who would like to become familiar with this topic and for experts being interested in the progress in this field. It will cover a broad range of studies ranging from examples of fundamental light-matter interaction in the quantum limit to devices capable of emitting single photons and entangled photon pairs on demand.