Bistability effect in the extreme strong coupling regime of the Jaynes-Cummings model

We study the nonlinear response of a driven cavity QED system in the extreme strong coupling regime where the saturation photon number is below one by many orders of magnitude. In this regime, multi-photon resonances within the Jaynes--Cummings spectrum up to high order can be resolved. We identify an intensity and frequency range of the external coherent drive for which the system exhibits bistability instead of resonant multi-photon transitions. The cavity field evolves into a mixture of the vacuum and another quasi-classical state well separated in phase space. The corresponding time evolution of the outgoing intensity is a telegraph signal alternating between two attractors

Scattering model description of cascaded cavity configurations

Cascaded optical cavities appear in various quantum information processing schemes in which atomic qubits are sitting in separate cavities interconnected by photons as flying qubits. The usual theoretical description relies on a coupled-mode Hamiltonian approach. Here we investigate the system of cascaded cavities without modal decomposition by using a scattering model approach and determine the validity regime of the coupled-mode models

Látható fénnyel gerjeszthető fotokatalizátorok előállítása és erre alapuló vízkezelési eljárások fejlesztése = Preparation of heterogeneous photo-catalysts excitable by visible light and development of water treatment processes using these catalysts

Jó minőségű, kicsiny szemcseméretű kompozit katalizátort állítottunk elő szol-gél eljárással. Lánghidrolízisen alapuló eljárást és készüléket fejlesztettünk ki fotokatalizátor előállítására. Fotokatalitikus modellkisérletekben teszteltük a katalizátorokat. Gázfázisú bontásokhoz tri- és tertraklór-etilént, vizes fázisú bontásokhoz fenolt és szalicilsavat használtunk modellanyagként. Eljárást dolgoztunk ki a fotokatalizátorok kerámia papír hordozóra való felvitelére. Víztisztításra használható nagylaboratóriumi méretű készüléket terveztünk és építettünk. A nagylaboratóriumi készülékben fenol és szalicilsav tartalmú oldatokat bontottunk. A berendezés és az eljárás működési paramétereit optimalizáltuk. | A coupled semiconductor characterized with small size and narrow size -distribution was syntetised by sol-gel procedure. Photocatalyst preparation procedure and apparatus, based on flame hydrolysis was developed. The photocatalysts prepared were characterized both by structural properties and phtocatalitic activities. Tricholro ethene and tetrachloroethene were used in gas phase and phenol and salicylic acid were the target compounds in aqueous solution. A procedure and technology was developed for the imobilization of photocatalysts on the surface of ceramic paper support. A pilot scale water treatment apparatus was designed and constructed using the catalysts imobilized to ceramic paper. The phenol and salicylic acid containig water was treated by using the above mentioned apparatus . The operation parameters of water treatment procedure and apparatus were optimised

Observation of the photon blockade breakdown phase transition

Nonequilibrium phase transitions exist in damped-driven open quantum systems when the continuous tuning of an external parameter leads to a transition between two robust steady states. In second-order transitions this change is abrupt at a critical point, whereas in first-order transitions the two phases can coexist in a critical hysteresis domain. Here, we report the observation of a first-order dissipative quantum phase transition in a driven circuit quantum electrodynamics system. It takes place when the photon blockade of the driven cavity-atom system is broken by increasing the drive power. The observed experimental signature is a bimodal phase space distribution with varying weights controlled by the drive strength. Our measurements show an improved stabilization of the classical attractors up to the millisecond range when the size of the quantum system is increased from one to three artificial atoms. The formation of such robust pointer states could be used for new quantum measurement schemes or to investigate multiphoton phases of finite-size, nonlinear, open quantum systems

Multi-cloud management strategies for simulating IoT applications

The Internet of Things (IoT) paradigm is closely coupled with cloud technologies, and the support for managing sensor data is one of the primary concerns of Cloud Computing. IoT-Cloud systems are widely used to manage sensors and different smart devices connected to the cloud, hence a large amount of data is generated by these things that need to be efficiently stored and processed. Simulation platforms have the advantage of enabling the investigation of complex systems without the need of purchasing and installing physical resources. In our previous work, we chose the DISSECT-CF simulator to model IoT-Cloud systems, and we also introduced provider pricing models to enable cost-aware policies for experimentation. The aim of this paper is to further extend the simulation capabilities of this tool by enabling multi-cloud resource management. In this paper we introduce four cloud selection strategies aimed to reduce application execution time and utilization costs. We detail our proposed method towards multi-cloud extension, and evaluate the defined strategies through scenarios of a meteorological application

Applying the Generalized Dombi Operator Family to the Speech Recognition Task

In the automatic speech recognition (ASR) problem, the task of constructing one word- or sentence-level probability from the available phoneme-level probabilities is a very important one. Here we try to improve the performance of ASR systems by applying operators taken from fuzzy logic which have the sort of properties this problem requires. In this paper we do this by using the Generalized Dombi Operator, which, by its two adjustable parameters and incorporating other well-known fuzzy operators, seems quite suitable. To properly adjust these parameters, we used the public optimization package called Snobfit. The results show that our approach is surprisingly successful: we were able to reduce the overall error rate by 53.4%