Seminars and Events

Seminars and Events

Colloquia

Coordinators: Silvia Gallego, Concepción Gutiérrez


05 November 2018, 12:00 h. Salón de Actos

2018 Nobel Prize in Physics: Electrodynamic Forces and Optical Tweezers. Its relevance in Biosciences

Manuel Nieto Vesperinas, ICMM-CSIC and Ricardo Arias, IMDEA Nanociencia


Arthur Ashkin, formerly at Bell Labs in New Jersey, Gérard Mourou from École Polytechnique in France and the University of Michigan, and Donna Strickland from the University of Waterloo in Canada, have been awarded the 2018 Nobel Prize in Physics “for groundbreaking inventions in the field of laser physics”.

The Royal Swedish Academy has honored Ashkin for inventing the optical tweezers, that trap and manipulate particles and living cells. This was a work done in the 1970s and 1980s, when he established a way to taming the radiation pressure of laser beams by discovering that it not only pushes small objects, but it also may confine them enabling their manipulation. He expanded these studies from latex beads to viruses, DNA and other biological pecimens, so that nowadays this tachnique constitutes a standard tool in biosciences and photonics.

On the other hand, Mourou and Strickland developed chirped pulse amplification, by which a laser pulse is stretched, amplified, and then compressed to increase its power. This has given rise to ultrafast, high-intensity lasers, paving the way to novel less invasive and accurate surgical tools, as well as to advances in data storage, materials manufacturing, and the study of femtosecond- and even attosecond-duration phenomena.

This talk will focus on the discovery of optical tweezers, addressing their evolution to constitute nowadays standard manipulation techniques in biological studies, as well as the progress and present knowledge of the optical forces which are beneath micro and nano-object manipulation.



15 October 2018, 12:00 h. Salón de Actos

Cambio climático: Observaciones, Proyecciones, Causas, Incertidumbres e Impactos

Ernesto Rodriguez Camino
Modelización y Evaluación del Clima, Agencia Estatal de Meteorología (AEMET)

El actual cambio climático de origen antropogénico es posiblemente uno de los problemas mayores con los que se enfrenta la humanidad tanto por su globalidad como por el alcance temporal de sus consecuencias. Después de analizar la magnitud del cambio climático observado, se discutirán en detalle las causas del mismo y se presentará una de la herramienta más comúnmente utilizadas para investigar y conocer el funcionamiento del sistema climático: los modelos acoplados océano-atmósfera. También se hará un breve recorrido histórico repasando los principales hitos, tanto los científicos que han marcado la evolución de nuestro conocimiento como los relativos a iniciativas internacionales que nos han conducido a acuerdos globales para enfrentarnos al cambio climático. También se repasarán las diferentes incertidumbres y lagunas de conocimiento que limitan nuestras estimaciones de la evolución futura del clima. Finalmente, se presentará de forma muy resumida los impactos del cambio climático en los diferentes sectores y regiones del globo y las diferentes alternativas para atajar el problema.



14 September 2018, 12:00 h. Salón de Actos

Quantum Computing with Spins in Silicon

Prof. Jason Petta
Princeton University, Department of Physics

Tremendous progress has been achieved in the coherent control of single quantum states (single charges, phonons, photons, and spins). At the frontier of quantum information science are efforts to hybridize different quantum degrees of freedom. For example, by coupling a single photon to a single electron fundamental light-matter interactions may be examined at the single particle level to reveal exotic quantum effects, such as single atom lasing. Coherent coupling of spin and light, which has been the subject of many theoretical proposals over the past 20 years, could enable a quantum internet where highly coherent electron spins are used for quantum computing and single photons enable long-range spin-spin interactions. In this colloquium I will describe experiments where we couple a single spin in silicon to a single microwave frequency photon. The coupling mechanism is based on spin-charge hybridization in the presence of a large magnetic field gradient. Spin-photon coupling rates gs/2 > 10 MHz are achieved and vacuum Rabi splitting is observed in the cavity transmission, indicating single spin-photon strong coupling. These results open a direct path toward entangling single spins at a distance using microwave frequency photons.



04 June 2018, 12:00 h. Salón de Actos

A review of Defects in Metal Dichalcogenides: Doping, Alloys, Interfaces, Vacancies and Their Effects in Catalysis & Optical Emission

Mauricio Terrones
The Pennsylvania State University, Univ. Park (USA) & Shinshu University,(JAPAN)

Two-dimensional transition metal dichalcogenides (TMDs) such as MoS2 and WS2 hold great promise for many novel applications. Recent years have witnessed tremendous efforts on large scale manufacturing of these 2D crystals. A long-standing puzzle in the field is the effect of different types of defects in their electronic, magnetic, catalytic and optical properties.

Here, an overview of different defects in TMDs will be presented. We will first focus on: 1) defining the dimensionalities and atomic structures of defects; 2) pathways to generating structural defects during and after synthesis and, 3) the effects of having defects on the physico-chemical properties and applications. We will also emphasize doping and allowing monolayers of MoS2 and WS2, and their implications in electronic and thermal transport, and describe the catalytic effects of edges, vacancies and local strain observed in MoxW(1-x)S2 monolayers by correlating the hydrogen evolution reaction with aberration corrected HRSTEM. Our findings demonstrates that it is now possible to use chalcogenide layers for the fabrication of more effective catalytic substrates. By studying photoluminescence spectra, atomic structure imaging, and band structure calculations, we demonstrate that the most dominating synthetic defect—S monovacancies in TMDs, is responsible for a new low temperature (T) excitonic transition peak in photoluminescence 300 meV away from the neutral exciton emission. These neutral excitons bind to S mono-vacancies at low T, and the recombination of bound excitons provides a unique spectroscopic signature of S mono-vacancies. At room T, this unique spectroscopic signature disappears due to thermal dissociation of bound excitons.



18 May 2018, 12:00 h. Salón de Actos

Science with X-ray Free-Electron Lasers

Massimo Altarelli
Max Planck Institute for Structure and Dynamics of Matter (Hamburg, Germany)

The discovery of X-rays in 1895 allowed the determination of the atomic structure of matter, the spatial arrangement of atoms in molecules and solids, and since then the science community has strived for ever more brilliant X-ray sources. It was recognized since the 1960’s that electron accelerators and storage rings, thanks to the phenomenon of synchrotron radiation, are the most powerful X-ray sources on Earth. In recent years, a further step was taken by sources based on linear accelerators, the Free-Electron Lasers, producing X-ray pulses with peak brilliance exceeding that of synchrotron beams by up to 9 orders of magnitude, with ultra-short duration, ~ 10 fs (10 -14 s), and with a high (laser-like) degree of transverse coherence. The latest and most powerful addition to the existing X-ray Free-Electron Lasers (XFEL’s), the European XFEL, resulting from the collaboration of 12 countries including Spain, and now operating in Hamburg, will be described, including the scientific motivations and the main features of the new source, comprising a 17.5 GeV superconducting linac accelerator, almost 2 km long, and three (later to be upgraded to five) undulators.

Examples of applications of the new sources to time-resolved studies in the sub-ps range (“molecular movies”) of chemical reactions, biochemical processes such as photosynthesis, and technologically relevant solid-state processes are briefly discussed, together with possible future developments.



09 April 2018, 12:00 h. Salón de Actos

La ciencia en la televisión del futuro

Graziella Almendral
INDAGANDO Televisión

Nunca antes se había consumido tanta televisión como ahora. Gracias a internet y las nuevas tecnologías podemos verla cómo, cuándo y dónde queramos. La TV por internet sustituirá a la tradicional como el móvil al fijo. Internet la ha acercado. Ahora la llevamos en el bolsillo y nos relacionamos con ella en cualquier momento. Ha permitido que el usuario consuma de forma más divertida y social los contenidos. Y entre ellos se encuentran los contenidos científicos.
Hoy en día internet y televisión son la principal fuente de información científica para el público general. Si quieres llegar al gran público, ésta es tu plataforma.
En esta charla viajaremos a la televisión presente y a la televisión del futuro. Analizaremos el impacto de las redes sociales que están presentes en los programas de televisión y que generan hasta 4 millones de tuits en un solo mes.
Y cómo no, hablaremos de la confusión actual entre opinión, comunicación e información y conoceremos las fuentes de información que generan las noticias actuales.
El objetivo es que el científico conozca el escenario en el que se moverá cuando quiera comunicar al gran público a través del principal medio de comunicación y del entorno actual en el que funciona.




15 March 2018, 12:00 h. Salón de Actos

The Nobel Prize in Physics 2017:
Spacetime ripples and flashes of light

José Antonio Font
Universidad de Valencia

On September 14 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected the first gravitational-wave signal, GW150914. This historical discovery confirmed a century-old prediction of Einstein’s theory of general relativity - the very existence of gravitational waves - and opened an entirely new way to study the cosmos. American scientists Rainer Weiss, Barry C. Barish, and Kip S. Thorne were awarded the Nobel Prize in Physics for the accomplishment. The breakthrough detection of the tiny ripples of spacetime generated when two black holes collide has been subsequently followed by three additional detections of binary black hole signals, GW151226, GW170104, and GW170814. The latter was jointly detected by LIGO and the European interferometer Virgo, which greatly enhanced the sky localization of the event. Only three days after the last binary black hole detection, the LIGO/Virgo detectors accomplished another tremendous achievement with the first observation of gravitational waves from a binary neutron star coalescence, GW170817. This time around, the spacetime ripples produced during the inspiral and merger of the two neutron stars were accompanied by flashes of light across the entire electromagnetic spectrum, and triggered an unprecedented multi-instrument observational campaign which has just opened the era of multi-messenger astronomical observations. This talk will discuss what are gravitational waves and how they are produced. It will also explore the theoretical and experimental efforts that have finally made possible the detection of gravitational waves, winding-up Einstein’s magnificent intellectual legacy on the centenary of the formulation of his theory of general relativity.



05 February 2018, 12:00 h. Salón de Actos

¿Por qué es necesario el 11 de febrero?

Pilar López Sancho
Instituto de Ciencia de Materiales de Madrid

El 22 de diciembre de 2015 la Asamblea General de Naciones Unidas proclamó el 11 de febrero como Día Internacional de las Mujeres y las Niñas en la Ciencia para “apoyar a las mujeres científicas y promover el acceso de las mujeres y las niñas a la educación, la capacitación y la investigación en los ámbitos de la tecnología, la ingeniería y las matemáticas, así como su participación en esas actividades, a todos los niveles”. En la justificación se puede leer: “los estereotipos discriminatorios han impedido el acceso en pie de igualdad de las mujeres y las niñas a la educación en los ámbitos de la ciencia, la tecnología, la ingeniería y las matemáticas. […] Estos estereotipos niegan a las mujeres y a las niñas la oportunidad de desarrollar su potencial y privan al mundo del ingenio y la innovación de la mitad de la población.”
En países desarrollados estas declaraciones pueden parecer exageradas, pero los datos que publica la Comisión Europea, recogidos en los 28 países comunitarios, indican que esos estereotipos no están erradicados. Desde hace varios años las mujeres reciben el 65% de los grados otorgados por las universidades públicas europeas y más del 47% de los doctorados, pero sólo el 21% de las cátedras de universidad. En el coloquio se dará una visión general de la situación de las mujeres en el sistema científico español y se analizarán las políticas y recomendaciones de la Comisión Europea encaminadas a mejorar el Espacio Europeo de Investigación.



09 January 2018, 12:00 h. Salón de Actos

Celebrating the Nobel Prize in Chemistry 2017
“Cryoelectron microscopy: the coming of age of a structural biology technique”

José María Valpuesta
Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain

Electron microscopy has been instrumental in the development of cellular and molecular biology over the last decades thanks to its use as a descriptive technique, capable of visualizing cellular and subcellular structures. However, although it is known since the 60s that electron microscopy is in principle capable of determining the structure of biological molecules even at atomic resolution, technical limitations had made this goal almost beyond reach. After a lengthy period of steady changes, however, a series of recent instrument developments and improved computer implementations has led to a revolution in the application of electron microscopy to structural biology, the so called “resolution revolution”. The awards to Jacques Dubochet, Joaquim Frank and Richard Henderson of the Nobel Prize in Chemistry 2017 give credit to some of the scientists who have made this revolution possible.



       

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