Material-barrier Tunneling in One-dimensional Few-boson Mixtures

We study the quantum dynamics of strongly interacting few-boson mixtures in one-dimensional traps. If one species is strongly localized compared to the other (e.g., much heavier), it can serve as an effective potential barrier for that mobile component. Near the limit of infinite localization, we map this to a system of identical bosons in a double well. For realistic localization, the backaction of the light species on the "barrier" atoms is explained--to lowest order--in terms of an induced attraction between these. Even in equilibrium, this may outweigh the bare intra-species interaction, leading to unexpected correlated states. Remarkably, the backaction drastically affects the inter-species dynamics, such as the tunneling of an attractively bound pair of fermionized atoms.Comment: 10 pages, 3 figure

Inter-species Tunneling in One-dimensional Bose Mixtures

We study the ground-state properties and quantum dynamics of few-boson mixtures with strong inter-species repulsion in one-dimensional traps. If one species localizes at the center, e.g., due to a very large mass compared to the other component, it represents an effective barrier for the latter and the system can be mapped onto identical bosons in a double well. For weaker localization, the barrier atoms begin to respond to the light component, leading to an induced attraction between the mobile atoms that may even outweigh their bare intra-species repulsion. To explain the resulting effects, we derive an effective Hubbard model for the lighter species accounting for the backaction of the barrier in correction terms to the lattice parameters. Also the tunneling is drastically affected: Varying the degree of localization of the "barrier" atoms, the dynamics of intrinsically noninteracting bosons can change from Rabi oscillations to effective pair tunneling. For identical fermions (or fermionized bosons) this leads to the tunneling of attractively bound pairs.Comment: 13 pages, 11 figures; v2 reflects major revisio

Optomechanics assisted with a qubit: From dissipative state preparation to many-body physics

We propose and analyze nonlinear optomechanical protocols that can be implemented by adding a single atom to an optomechanical cavity. In particular, we show how to engineer the environment in order to dissipatively prepare the mechanical oscillator in a superposition of Fock states with fidelity close to one. Furthermore, we discuss how a single atom in a cavity with several mechanical oscillators can be exploited to realize nonlinear many-body physics by stroboscopically driving the mechanical oscillators. We show how to prepare non-classical many-body states by either applying coherent protocols or engineering dissipation. The analysis of the protocols is carried out using a perturbation theory for degenerate Liouvillians and numerical tools. Our results apply to other systems where a qubit is coupled to a mechanical oscillator via a bosonic mode, e.g., in cavity quantum electromechanics

Master equation approach to optomechanics with arbitrary dielectrics

We present a master equation describing the interaction of light with dielectric objects of arbitrary sizes and shapes. The quantum motion of the object, the quantum nature of light, as well as scattering processes to all orders in perturbation theory are taken into account. This formalism extends the standard master equation approach to the case where interactions among different modes of the environment are considered. It yields a genuine quantum description, including a renormalization of the couplings and decoherence terms. We apply this approach to analyze cavity cooling of the center-of-mass mode of large spheres. Furthermore, we derive an expression for the steady-state phonon numbers without relying on resolved-sideband or bad-cavity approximations.Comment: 17 pages, 5 figure

FPGA acceleration of reference-based compression for genomic data

One of the key challenges facing genomics today is efficiently storing the massive amounts of data generated by next-generation sequencing platforms. Reference-based compression is a popular strategy for reducing the size of genomic data, whereby sequence information is encoded as a mapping to a known reference sequence. Determining the mapping is a computationally intensive problem, and is the bottleneck of most reference-based compression tools currently available. This paper presents the first FPGA acceleration of reference-based compression for genomic data. We develop a new mapping algorithm based on the FM-index search operation which includes optimisations targeting the compression ratio and speed. Our hardware design is implemented on a Maxeler MPC-X2000 node comprising 8 Altera Stratix V FPGAs. When evaluated against compression tools currently available, our tool achieves a superior compression ratio, compression time, and energy consumption for both FASTA and FASTQ formats. For example, our tool achieves a 30% higher compression ratio and is 71.9 times faster than the fastqz tool

Large Quantum Superpositions and Interference of Massive Nanometer-Sized Objects

We propose a method to prepare and verify spatial quantum superpositions of a nanometer-sized object separated by distances of the order of its size. This method provides unprecedented bounds for objective collapse models of the wave function by merging techniques and insights from cavity quantum optomechanics and matter wave interferometry. An analysis and simulation of the experiment is performed taking into account standard sources of decoherence. We provide an operational parameter regime using present day and planned technology.Comment: 4 pages, 2 figures, to appear in PR

Proposta de projeto de disciplina optativa na modalidade à distância

Orientador : Prof. Dr. Ricardo Antunes de SáMonografia (especialização) - Universidade Federal do Paraná, Setor de Educação, Curso de Especialização em Educação a DistânciaInclui referênciasResumo: A proposta desta disciplina visou apresentar fundamentos em Geoestatística à alunos de graduação, sendo esta de caráter eletivo e optativo. Após várias discussões resolvemos tomar a iniciativa de inserir a modalidade de EaD dentro do curso de Graduação em Estatística, mesmo que sendo apenas como disciplina optativa, sendo esta piloto no curso, por pensarmos que a Educação a Distância (EaD) adquire, então, importância não apenas como forma de superar problemas pontuais, mas também como alternativa para atender a demandas de públicos específicos, visto que há dificuldades na composição da grade horária para oferta de disciplinas optativas no curso em questão. Baseamos-nos na Portaria 4.059 de 10/12/2004 que estabelece, em seu artigo 1º, que as "(...) instituições de ensino superior poderão introduzir, na organização pedagógica e curricular de seus cursos superiores reconhecidos, a oferta de disciplinas integrantes do currículo que utilizem modalidade semi-presencial, com base no art. 81 da Lei nº 9.394, de 1.996, e no disposto nesta Portaria." Seguindo este pensamento o nosso desafio é conhecer as diversas tecnologias da informação e da comunicação, estar aberto às mudanças, procurar entendê-las e ter disposição para atuar em cenários diferentes.Abstract: The course purpose was to present a fundamentals Geostatistics for undergraduates, as elective and optional course. After several discussions we decided to enter the a distance education mode within the Undergraduate course in statistics, even if only as being elective, and this pilot course, because we think that the a Distance Education (DE) acquires then importance not only as a way to overcome specific problems, but also as an alternative to meet the specific audience demands, as difficulties in the timetable composition for offering this course as a elective course. We base ourselves on the Ordinance 4059 of 10/12/2004 establishing in its Article 1, that "(...) higher education institutions may introduce in the pedagogical and curriculum of their recognized degree courses, the provision of the curriculum disciplines that use the semi-presencial mode, based on art. 81 of Law No. 9,394, of 1996, and on provisions of this Ordinance." Following this thought our challenge is to know a variety of information technologies and communication, being open to change, seek to understand them and be willing to work in different scenarios