Quantum Computing (quantum + computing)

Distribution by Scientific Domains

Selected Abstracts

Quantum degenerate potassium-rubidium mixtures

G. Modugno
We report on the production of quantum degenerate mixtures of potassium and rubidium isotopes, by means of evaporative cooling in a magnetic trap. Specifically, we produce a Bose,Bose mixture with 41K and 87Rb and Fermi,Bose mixture with 40K and 87Rb. Application of association schemes in these systems may allow the production of degenerate gases of heteronuclear molecules of both bosonic and fermionic character. Ultracold dipolar molecules have been recognized as a viable candidate for the implementation of quantum computing. [source]

Lie Theory for Quantum Control

G. Dirr
Abstract One of the main theoretical challenges in quantum computing is the design of explicit schemes that enable one to effectively factorize a given final unitary operator into a product of basic unitary operators. As this is equivalent to a constructive controllability task on a Lie group of special unitary operators, one faces interesting classes of bilinear optimal control problems for which efficient numerical solution algorithms are sought for. In this paper we give a review on recent Lie-theoretical developments in finite-dimensional quantum control that play a key role for solving such factorization problems on a compact Lie group. After a brief introduction to basic terms and concepts from quantum mechanics, we address the fundamental control theoretic issues for bilinear control systems and survey standard techniques fromLie theory relevant for quantum control. Questions of controllability, accessibility and time optimal control of spin systems are in the center of our interest. Some remarks on computational aspects are included as well. The idea is to enable the potential reader to understand the problems in clear mathematical terms, to assess the current state of the art and get an overview on recent developments in quantum control-an emerging interdisciplinary field between physics, control and computation. ( 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Quantum computing measurement and intelligence

Zoheir Ezziane
Abstract One of the grand challenges in the nanoscopic computing era is guarantees of robustness. Robust computing system design is confronted with quantum physical, probabilistic, and even biological phenomena, and guaranteeing high-reliability is much more difficult than ever before. Scaling devices down to the level of single electron operation will bring forth new challenges due to probabilistic effects and uncertainty in guaranteeing "zero-one" based computing. Minuscule devices imply billions of devices on a single chip, which may help mitigate the challenge of uncertainty by replication and redundancy. However, such device densities will create a design and validation nightmare with the sheer scale. The questions that confront computer engineers regarding the current status of nanocomputing material and the reliability of systems built from such minuscule devices are difficult to articulate and answer. This article illustrates and discusses two types of quantum algorithms as follows: (1) a simple quantum algorithm and (2) a quantum search algorithm. This article also presents a review of recent advances in quantum computing and intelligence and presents major achievements and obstacles for researchers in the near future. 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 [source]

QD technology and market prospects in the sectors of space exploration, biomedicine, defense, and security

C. A. Charitidis
Abstract Quantum dots (QD) are a unique subset of nanomaterials characterized by their extraordinary quantum confinement behaviour. Even though the quantum dot industry is still in its infancy with revenues now reaching $10 million, it is expected to surpass $500 million in 2009. However, in order to leverage the full potential of the QD technology, new fabrication processes must be developed to attain high detectivity and high operating temperature (HOT) photodetector devices. The Quantum Dot Infrared Photodetectors (QDIPs) possess an immense potential for civilian and military applications due to the distinct characteristics stemming from their dimensionality , which provides 3D carrier confinement and the capacity for normal-incidence detection , and their amenability to bandgap engineering , which allows tailoring the peak and cutoff wavelengths according to custom needs. The QDIPs, especially when optimized to operate at higher temperatures, can become critical components in space exploration, defence and security, optical communication, quantum computing and cryptography, and medical imaging applications. Robust and reliable solutions for these fields will command a premium position in the marketplace as by responding to the societal need for secure electronic transactions, exponentially faster data processing, and higher quality diagnostic tools. ( 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]