(Português) Programa de Pós-Graduação em Física da UFSC, Florianópolis
  • Examen de Cualificación al Doctorado de Carline Biesdorf – 1 de diciembre de 2021 – Miércoles – 10:00 am

    Publicado em 25/11/2021 às 15:58 03Thu, 25 Nov 2021 15:58:35 +000035.

    El Programa de Posgrado en Física invita a todos para:

    Examen de Cualificación al Doctorado

    Carline Biesdorf

    MODIFICAÇÕES NO MODELO DA SACOLA DO MIT E DIAGRAMAS DE FASES DA QCD

     

    Jurados

    Profª. Drª. Débora Peres Menezes – (presidente) – UFSC/FSC

    Prof. Dr. Marcelo Dallagnol Alloy – (miembro titular) – UFSC/Blumenau

    Prof. Dr. Luiz Laércio Lopes – (miembro externo) – CEFET/MG

    Prof. Dr. Celso de Camargo Barros Junior – (miembro titular) – UFSC/FSC

    Prof. Dr. Tiago José Nunes da Silva – (miembro titular) – UFSC/FSC

    Fecha: 1 de diciembre de 2021quarta-feira – Horario: 10:00 am – Lugar: a través de la plataforma Google Meet

     

     Enlace de acceso a la sala virtual: https://meet.google.com/reu-rgkr-kct


  • Seminário con Arthur Alencastro Puls- 26 de noviembre de 2021 (viernes) – 10:15 a.m.

    Publicado em 22/11/2021 às 19:25 07Mon, 22 Nov 2021 19:25:58 +000058.

    EL PROGRAMA DE POSGRADO EN FÍSICA invita a todos para lo seminario:

    Detailed chrono-chemo-dynamics of seven metal-poor red giants from Kepler

    Arthur Alencastro Puls

    Research School of Astronomy and Astrophysics, Australian National University

    Resumen:

    The Kepler mission has yielded a revolution in the field of GalacticArchaeology, with its photometry allowing the determination of stellar parameters with an unprecedented level of precision for Red Giant stars. Recent studies have shown that a few of these objects display conflicting characteristics in the age-metallicity space (e.g., young and metal-poor). In this project we combine asteroseismic information from solar-like oscillations, high-resolution spectroscopy and Gaia astrometry to derive stellar ages, chemical abundances and kinematics for a group of metal-poor Red Giants, and characterise them in a multidimensional chrono-chemo-dynamical space. Our results suggest that underestimated parallax errors make the effect of Gaia parallaxes more important than different choices of model grid or – in the case of stars ascending the RGB – mass-loss prescription. Two stars are identified as potentially evolved halo blue stragglers. Four objects are likely members of the accreted Milky Way halo, and their possible relationship with known accretion events, such as Gaia-Sausage and Gaia-Sequoia, is discussed.

    Fecha: 26 de noviembre de 2021 – (viernes) – Horário: 10:15 a.m.

    Enlace acceso al canal de youtube: https://youtu.be/D1pIcDUoHds


  • Seminário con Prof. Dr. Raphael Ribeiro- 19 de noviembre de 2021 (viernes) – 10:15 a.m.

    Publicado em 16/11/2021 às 12:55 12Tue, 16 Nov 2021 12:55:34 +000034.

    EL PROGRAMA DE POSGRADO EN FÍSICA invita a todos para lo seminario:

    Chemistry in optical microcavities: Spectral fluctuations and energy transport

    Prof. Dr. Raphael Ribeiro

    Department of Chemistry, Emory University – Atlanta, USA

    Resumen:

    Optical cavities and metallic nanoparticles confine electromagnetic fields and enable new pathways to control physicochemical processes via strong light-matter interactions. In fact, recent experiments have shown that photonic and plasmonic materials may induce significant and sometimes unexpected changes to physical properties and reactivity of molecular systems. In this talk, I will introduce and present the key results of our recent theoretical investigations on the effects of collective radiation-matter interactions on transport and spectral properties of disordered molecular ensembles hosted by a resonant 1D optical cavity (photonic wire). The main implications of our findings to future theoretical and experimental research will be discussed. I will show that widely employed minimal theoretical models fail to adequately describe photonic effects on the local properties of chemical systems and explain strategies to maximize the influence of optical cavities on molecular materials informed by our simulations.

    Fecha: 19 de noviembre de 2021 – (viernes) – Horário: 10:15 a.m.

    Enlace acceso al canal de youtube: https://youtu.be/8nV3QDFmhB8


  • Seminário con Prof. Dr. Emanuele Orgiu- 12 de noviembre de 2021 (viernes) – 10:15 a.m.

    Publicado em 08/11/2021 às 15:42 03Mon, 08 Nov 2021 15:42:03 +000003.

    EL PROGRAMA DE POSGRADO EN FÍSICA invita a todos para lo seminario:

    What Hampers Electron Transport in Organic Crystals? A Close Look at Band-like Transport in N-type Organic Semiconductors

    Prof. Dr. Emanuele Orgiu

    Institut National de la Recherche Scientifique – INRS, Québec – Canada

    Resumen:

    Charge transport in organic semiconductors is notoriously sensitive to the presence of disorder, both intrinsic and extrinsic, especially for n-type materials. Intrinsic dynamic disorder stems from large thermal fluctuations both in intermolecular transfer integrals and (molecular) site energies in weakly interacting van der Waals solids and sources transient localization of the charge carriers. The molecular vibrations that drive transient localization typically operate at low-frequency (< a-few-hundred cm-1), which makes it difficult to assess them experimentally. Hitherto, this has prevented the identification of clear molecular design rules to control and reduce dynamic disorder. In addition, the disorder can also be extrinsic, being controlled by the chemical and physical «coupling» of the π-conjugated core to the gate dielectric. During the Colloquium, I will present a comprehensive study of charge transport in two closely related n-type molecular organic semiconductors using a combination of temperature-dependent inelastic neutron scattering and photoelectron spectroscopy corroborated by electrical measurements, theory and simulations. By doing so, unambiguous evidence is provided that ad hoc molecular design enables to free the electron charge carriers from both intrinsic and extrinsic disorder to ultimately reach band-like electron transport.

    Fecha: 12 de noviembre de 2021 – (viernes) – Horário: 10:15 a.m.

    Enlace acceso al canal de youtube: https://youtu.be/TE3LD1NKi4c


  • Seminário con Prof. Dr. Lucas Chibebe Céleri- 5 de noviembre de 2021 (viernes) – 10:15 a.m.

    Publicado em 01/11/2021 às 09:05 09Mon, 01 Nov 2021 09:05:44 +000044.

    EL PROGRAMA DE POSGRADO EN FÍSICA invita a todos para lo seminario:

    Gauge invariant quantum thermodynamics: consequences for the first law

    Prof. Dr. Lucas Chibebe Céleri

    Instituto de Física – UFG

    Resumen:

    Universality of classical thermodynamics rests on the central limit theorem, due to which measurements of thermal fluctuations are unable to reveal detailed information regarding the microscopic structure of a macroscopic body. When small systems are considered and fluctuations become important, thermodynamic quantities can be understood in the context of classical stochastic mechanics. A fundamental assumption behind thermodynamics is therefore that of coarse-graining, which stems from a substantial lack of control over all degrees of freedom. However, when quantum systems are concerned, one claims a high level of control. As a consequence, information theory plays a major role in the identification of thermodynamic functions. Here, drawing from the concept of gauge symmetry, essential in all modern physical theories, a new, intermediate, route is put forward. Working within the realm of quantum thermodynamics, a physically motivated gauge transformation, which encodes a gentle variant of coarse-graining behind thermodynamics, is explicitly constructed . As a consequence, quantum work and heat are reinterpreted, as well as the role of quantum coherence.

    Fecha: 5 de noviembre de 2021 – (viernes) – Horário: 10:15 a.m.

    Enlace acceso al canal de youtube: https://youtu.be/ieeh_LtXBgI


  • Seminário con Dr. Rafael Bento Serpa- 29 de octubre de 2021 (viernes) – 10:15 a.m.

    Publicado em 25/10/2021 às 15:52 03Mon, 25 Oct 2021 15:52:41 +000041.

    EL PROGRAMA DE POSGRADO EN FÍSICA invita a todos para lo seminario:

    Virtual-Slit Focusing in a Cycloidal Mass Spectrometer – A Proof of Concept

    Dr. Rafael Bento Serpa

    Postdoctoral Associate | Duke University Nanomaterials and Thin Films Lab

    Resumen:

    This work demonstrates a novel approach to mass spectrometry using the “virtual-slit” created by the small, spatial volume from which ions are generated by localized ionization techniques (e.g., laser ionization of particles and surfaces, and spark ionization). That is, the volume in which the ions are generated creates a localized source of ions in much the same way as a slit that allows only ions from a specific cross-sectional area to pass. As demonstrated in this work, the unique perfect focusing properties of a cycloidal mass analyzer can enable the localized ionization volume to function as a virtual slit. In this manuscript, we provide a proof-of-concept (POC) demonstration of a virtual-slit cycloidal mass spectrometer (VS-CyMaS) consisting of a cycloidal mass analyzer, a laser ionization source, and an ion array detector. The laser is used to ionize either bulk or thin-film samples of Cu, Ti, Ni, and Cr. Results indicate that the width of the peaks at the detector is the same as the laser spot size, validating the concept of virtual-slit focusing. Furthermore, the material ablated with each laser pulse for Ti and Cu is estimated at 60 and 140 fg, respectively, indicating that a very low detection limit is possible given the ability of the cycloidal mass analyzer to collect ions generated by laser ionization that have wide energy and angular dispersions.

    Fecha: 29 de octubre de 2021 – (viernes) – Horário: 10:15 a.m.

    Enlace acceso al canal de youtube: https://youtu.be/t75RNYAdy1s


  • (Português) Defesa de tese de Everton Botan – 29 de outubro de 2021 – sexta-feira – Horário: 9h30min

    Publicado em 20/10/2021 às 12:28 12Wed, 20 Oct 2021 12:28:01 +000001.

    Sustentación de Tesis

    Everton Botan
    IDENTIFICAÇÃO DE ESTRELAS VARIÁVEIS NO VVV E INVESTIGAÇÃO DE ESTRUTURAS NO BOJO GALÁCTICO 

    Jurados:

    Prof. Dr. Roberto Kalbusch Saito – (presidente) – UFSC/FSC

    Prof. Dr. Jacques Raymond Daniel Lepine – (miembro externo) – IAG/USP

    Prof. Dr. Helio Jaques Rocha-Pinto – (miembro externo) – Observatório do Valongo – UFRJ

    Prof. Dr. Daniel Ruschel Dutra – (membro titular) – UFSC/FSC

    Prof. Dr. Antônio Nemer Kanaan Neto – (miembro titular) – UFSC/FSC

    Fecha: 29 de octubre de 2021 viernes – Horario: 9:30 am – Lugar: videoconferencia

    Enlace de acceso a sala virtual: https://meet.google.com/dof-hsws-ezf

     


  • Seminário con Dr. Omar Roldán- 22 de octubre de 2021 (viernes) – 10:15 a.m.

    Publicado em 19/10/2021 às 11:28 11Tue, 19 Oct 2021 11:28:45 +000045.

    EL PROGRAMA DE POSGRADO EN FÍSICA invita a todos para lo seminario:

    Aberration and Doppler effect on the CMB: kinematical and intrinsic contributions

    Dr. Omar Roldán

    Pós-doutorando – UFRJ

    Resumen:

    The aberration and Doppler coupling effects of the Cosmic Microwave Background (CMB) were measured by the Planck satellite. The most straightforward interpretation leads to a direct detection of our peculiar velocity, consistent with the measurement of the well-known dipole. We show however, that in some cases a primordial dipolar potential can also produce such effects. But in addition it produces other signatures due to integrated terms which we will discuss in some detail. We also discuss how aberration measurements can be used to constraint some models which introduce super-horizon perturbations to explain the hemispherical asymmetry. This work has also been used to infer the Intrinsic Dipole. Finally we also discuss about CMB anisotropies at all orders and the non-linear Sachs-Wolfe formula.

    Most of the seminar is based on the paper:
    https://arxiv.org/abs/1603.02664
    https://arxiv.org/abs/1706.08428
    Other References:
    https://arxiv.org/abs/1708.00441
    https://arxiv.org/abs/2011.08385

    Fecha: 22 de octubre de 2021 – (viernes) – Horário: 10:15 a.m.

    Enlace acceso al canal de youtube: https://youtu.be/sqea8-jX35Q


  • Seminário con Prof. Dr. Luis Guilherme de Carvalho Rego- 15 de octubre de 2021 (viernes) – 10:15 a.m.

    Publicado em 11/10/2021 às 18:24 06Mon, 11 Oct 2021 18:24:31 +000031.

    EL PROGRAMA DE POSGRADO EN FÍSICA invita a todos para lo seminario:

    Transporte eletrônico em nanoestruturas com quiralidade

    Prof. Dr. Luis Guilherme de Carvalho Rego

    Departamento de Física, UFSC

    Resumen:

    A quiralidade geométrica é facilmente percebida em uma figura cuja imagem no espelho não pode ser superposta com ela mesma. No entanto, o conceito de quiralidade dinâmica tem mais relevância, pois conecta o mundo observável com propriedades fundamentais da natureza. Neste trabalho (DOI:10.1021/acs.nanolett.1c02636) investigamos a propagação de elétrons em nanofios helicoidais e verificamos que a interação entre momento angular de spin e a quiralidade do nanofio, interligados pela interação spin-órbita, gera uma assimetria na direção de propagação das partículas. O efeito é induzido pela quebra de paridade, causada pela quiralidade da estrutura molecular do fio. Para realizar este estudo utilizamos um modelo microscópico que leva em consideração a interação spin-órbita no material. Os cálculos são aplicados a um novo material, uma cadeia dupla hélice totalmente inorgânica feita do material SnIP, que é um semicondutor com bandgap de ~ 1,9 eV. Por fim, consideramos a relação deste efeito com fenômenos associados, dentre eles: polarização de spin induzida por quiralidade (efeito CISS), propagação de carga em nanotubos de carbono, e atividade óptica em materiais quirais e metamateriais.

    Fecha: 15 de octubre de 2021 – (viernes) – Horário: 10:15 a.m.

    Enlace acceso al canal de youtube: https://youtu.be/3vvnv2iGHVU 

     


  • Sustentación de Tesis de de Wagner Schlindwein – 15 de octubre de 2021 – viernes – Horario: 9:30 am

    Publicado em 08/10/2021 às 15:30 03Fri, 08 Oct 2021 15:30:08 +000008.

    El programa de Posgrado en Fisica invita a todos para la:

    Sustentación de Tesis

    Wagner Schlindwein

    MODELANDO ERUPÇÕES EM NOVAS-ANÃS COMO EVENTOS DE TRANSFERÊNCIA DE MATÉRIA

    Jurados:

    Prof. Dr. Raymundo Baptista – (presidente) – UFSC/FSC

    Profª. Drª. Cláudia Vilega Rodrigues – (miembro externo) – INPE/MCT

    Prof. Dr. Alex Cavaliéri Carciofi – (miembro externo) – IAG/USP

    Prof. Dr. Roberto Kalbusch Saito – (membro titular) – UFSC/FSC

    Prof. Dr. Bernardo Walmott Borges – (miembro titular) – Araranguá/UFSC

    Prof. Dr. André Luiz de Amorim – (miembro titular) – UFSC/FSC 

    Fecha: 15 de octubre de 2021 viernes – Horario: 9:30 am

    Enlace de acceso a sala virtual: https://conferenciaweb.rnp.br/webconf/raymundo


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