Search results for "simulator"
showing 10 items of 188 documents
Experimental demonstration of single-site addressability in a two-dimensional optical lattice
2009
We demonstrate single site addressability in a two-dimensional optical lattice with 600 nm lattice spacing. After loading a Bose-Einstein condensate in the lattice potential we use a focused electron beam to remove atoms from selected sites. The patterned structure is subsequently imaged by means of scanning electron microscopy. This technique allows us to create arbitrary patterns of mesoscopic atomic ensembles. We find that the patterns are remarkably stable against tunneling diffusion. Such micro-engineered quantum gases are a versatile resource for applications in quantum simulation, quantum optics and quantum information processing with neutral atoms.
Colloquium: Trapped ions as quantum bits -- essential numerical tools
2009
Trapped, laser-cooled atoms and ions are quantum systems which can be experimentally controlled with an as yet unmatched degree of precision. Due to the control of the motion and the internal degrees of freedom, these quantum systems can be adequately described by a well known Hamiltonian. In this colloquium, we present powerful numerical tools for the optimization of the external control of the motional and internal states of trapped neutral atoms, explicitly applied to the case of trapped laser-cooled ions in a segmented ion-trap. We then delve into solving inverse problems, when optimizing trapping potentials for ions. Our presentation is complemented by a quantum mechanical treatment of…
Quantum simulation of the cooperative Jahn-Teller transition in 1D Ion crystals
2012
The Jahn-Teller effect explains distortions and nondegenerate energy levels in molecular and solid-state physics via a coupling of effective spins to collective bosons. Here we propose and theoretically analyze the quantum simulation of a many-body Jahn-Teller model with linear ion crystals subjected to magnetic field gradients. We show that the system undergoes a quantum magnetic structural phase transition which leads to a reordering of particle positions and the formation of a spin-phonon quasicondensate in mesoscopic ion chains.
Quantum Control in Atomic Systems
1999
We review a series of recent experiments demonstrating quantum control of atomic processes and products induced by the interaction of the atom with coherent bichromatic electromagnetic fields. Since the effects under consideration are electromagnetically induced, control is established through the field parameters i.e. frequency, amplitude and phase. The controlled processes include resonant and non resonant multiphoton ionization, autoionization, radiative decay in multiple continua (ionization branching ratios) and third harmonic generation.
Applications of Quantum Mechanics
2013
Quantum mechanics provides the basis for most fields of modern physics and there are many well advanced methods of practical solution of specific and topical problems
Optical control of entangled states in semiconductor quantum wells
2012
We present theory and calculations for coherent high-fidelity quantum control of many-particle states in semiconductor quantum wells. We show that coupling a two-electron double quantum dot to a terahertz optical source enables targeted excitations that are one to two orders of magnitude faster and significantly more accurate than those obtained with electric gates. The optical fields subject to physical constraints are obtained through quantum optimal control theory that we apply in conjunction with the numerically exact solution of the time-dependent Schrödinger equation. Our ability to coherently control arbitrary two-electron states, and to maximize the entanglement, opens up further pe…
Modeling risk perception in ATIS context through Fuzzy Logic
2011
Abstract This research is aimed at investigating the effect of accuracy of ATIS (Advanced Traveller Information Systems) in terms of route choices and travellers concordance to informative system. A Stated Preference Experiment has been made by using a Travel Simulator developed at the Technische Universiteit of Delft (The Netherlands). During the experiment respondents have been asked to make repeated route choices in presence of ATIS. Two kinds of information have been tested: descriptive (respondents are provided with the estimated travel times on each route), and prescriptive (respondents are provided with the estimated shortest route). For each kind of information four levels of accura…
Self-configuring multipath intra-mesh infrastructure QoS based routing
2016
International audience; Multi-path routing concept was largely exploited in wireless networks to provide benefits such as fault tolerance, load balancing, performance improvement in terms of latency, etc. In this paper, we propose a multi-path routing based protocol named MP-IMRR (Multi-path Intra-Mesh infrastructure Routing protocol) to improve our previously defined QoS based routing protocol for wireless mesh networks (i.e. IMRR). MP-IMRR is defined in order to achieve better reactivity and faster recovery from eventual route failures than the IMRR protocol by adopting the backup routes concept. Besides, given the complexity increase while considering network management systems, we adopt…
Multi-Connectivity for User Throughput Enhancement in 5G Non-Terrestrial Networks
2022
To meet the increasing throughput and reliability demands, satellites may be used to complement the Fifth Gener-ation (5G) Terrestrial Networks (TNs). To increase the efficiency of the satellite communications involved, research on bandwidth-efficient techniques is needed. Multi-Connectivity (MC), where a user can be connected to multiple Next Generation Node Bs (gNBs) simultaneously, is one of such techniques. In this paper, the focus is on MC in NonTerrestrial Networks (NTNs) to improve users' experienced throughputs. First, a study of relevant specifications and algorithms is conducted. Then, the designed load-aware Secondary Node (SN) addition and traffic steering algorithms are present…
Tunable Polarons in Bose-Einstein Condensates
2017
A toolbox for the quantum simulation of polarons in ultracold atoms is presented. Motivated by the impressive experimental advances in the area of ultracold atomic mixtures, we theoretically study the problem of ultracold atomic impurities immersed in a Bose-Einstein condensate mixture (BEC). The coupling between impurity and BEC gives rise to the formation of polarons whose mutual interaction can be effectively tuned using an external laser driving a quasi-resonant Raman transition between the BEC components. Our scheme allows one to change the effective interactions between polarons in different sites from attractive to zero. This is achieved by simply changing the intensity and the frequ…