DFA Talks

The Instituto de Astrofísica e Ciências do Espaço (IA) is a research infrastructure with a national dimension. Currently the institute is the largest research unit of the area of Space Sciences in Portugal, being responsible for the majority of the national productivity in international ISI journals in this area. The research and development effort at the IA includes most of the topics presently, and for the next decade, at the forefront of research in Astrophysics and Space Sciences, from the Solar System to the large-scale properties of the Universe, complemented by work on instrumentation and systems with potential use in Astronomy and Astrophysics projects. 

The Institute of Physics for Advanced Materials, Nanotechnology and Photonics (IFIMUP) is a physics Research Unit of the University of Porto, operating at Faculty of Sciences aiming to carry out research over a wide range of topics focused on the innovative physical properties of materials at different scales, boosting the development of new technologies in order to contribute to solve today’s Grand Challenges.

Following an introduction of the institute and of the several opportunities here, there will be talks by junior and senior researchers about a wide range of topics.

IFIMUP and its opportunities

Prof. João Pedro Araújo

The main research activities carried out at IFIMUP will be presented, as well as some of the research opportunities that exist at IFIMUP.

Printing the Future with Flexible Sensors

Dr. Ana Pires, Junior Researcher

Flexible printed sensors represent a growing worldwide market with a CAGR of up to 28% of year, ranging in applications from human-machine interfaces to environmental sensing. At IFIMUP, printed electronics have been used in several areas, including electronic textiles, energy harvesting systems, electronic tattoos, etc. Through the emergence of nanomaterials and their improvement of performance, innovative devices are being produced. The use of plastic substrates or textiles offers manufacturing advantages allied with excellent mechanical flexibility, weight reduction, and adaptability. In this talk, the 5-years IFIMUP working and knowledge in printing and flexible sensors will be presented.

Magnetic nanostructures for biomedical applications

Dr. Célia Sousa, Senior Researcher

Magnetic nanostructures have been widely studied due to its potential applicability into several research fields such as data storage, sensing and biomedical applications. Focusing on the biomedical aspect, few new approaches on cancer therapy are deserving of mention: magnetic fluid hyperthermia, drug targeting and magneto-mechanically induced cell death [1]. In this talk, the most recent IFIMUP results in this field will be presented from the micromagnetic simulations of high-aspect-ratio nanowires and vortex nanodiscs, to their functionalization, cell internalization and biocompatibility.

References

¹  L. Peixoto, R. Magalhães, D. Navas, S. Moraes, C. Redondo, R. Morales, J. P. Araújo, C.T. Sousa, Magnetic nanostructures for emerging biomedical applications. Appl. Phys. Rev., in press (2019).

Improving magnetoelectric multiferroic materials via atomic substitution, strain engineering and ultrafast light-pulses

Dr. Rui Vilarinho, Junior Researcher

Magnetoelectric coupling in multiferroics is a Holy Grail of solid-state physics, yet they are scarce. Multiferroics are materials that show more than one ferroic order, i.e., a coexistence of either ferro- or antiferro-magnetism, -electricity or -elasticity. Among them, the coexistence of magnetic and polar orders is the most interesting for applications, in particular when there is a cross-coupling between them, designed as magneoelectricity, meaning the magnetic order is sensitive to an applied electric field and the polar order sensitive to an applied magnetic field. The main mechanism that gives origin to magnetoelectric multiferroics is the stabilization of a spatially varying magnetization (i.e., modulated), whose magnetic order not only breaks time reversal but also breaks the spatial inversion, needed for ferroelectricity to emerge. Still, very few materials present it and the magnetoelectric coupling is usually small [1,2].

“Centro de Física do Porto” (CFP) is the University of Porto unit of the research center CF-UM-UP (Centro de Física das Universidades do Minho e do Porto). The unit is located in the Physics Department of the Faculty of Sciences, and is fully devoted to research in theoretical physics, in the broad area of Quantum Physics and Fields in High Energy and Condensed Matter, exploring synergies between theorists of different fields.

Theoretical physics research at University of Porto

Prof. Eduardo Castro

A short presentation about the main research activities developed at the Centre of Physics of Porto (Centro de Física do Porto – CFP).

How to learn about quantum gravity by studying magnets

António Antunes, PhD student

Conformal field theories (CFTs) are universal objects which describe the physics of many different realms, including statistical mechanics, condensed matter physics, particle physics and string theory. Starting from the simple example of a magnet, we will go through the basics of CFTs with an emphasis on the physical principles of conformal invariance, unitarity and Bose/Fermi symmetry which give rise to the conformal bootstrap philosophy. This approach, based only on elementary consistency requirements, allows us to solve otherwise intractable systems with unprecedented accuracy. Finally, we will sketch the relation between CFTs and theories of quantum gravity.

From Fundamental Physics to Climate Change

Prof. Orfeu Bertolami

In this talk two issues of fundamental physics will be discussed, namely a proposal for dark matter and an alternative theory of gravity. It will be also shown how fundamental physics can provide an approach to understand the evolution of the Earth System driven by the human action in the Anthropocene. 

What can Computers Tell us about the Quantum Mechanics of Disordered Electrons?

João Pires, PhD student

Most of our knowledge on the quantum physics of electrons in crystalline matter is based on Bloch’s Theorem [1]. This important result states that electrons move like plane-waves across any spatially periodic potential and forms the basis of the electronic band theory of solids. Despite its success in explaining most properties observed in real-life conductors and semi- conductors, exceptional phenomena are known to be caused by (the ubiquitous) deviations from a perfect crystalline order. Paradigmatic examples of disorder-controlled physics phenomena can be traced back to the proposals of P. W. Anderson [2], who discovered that disorder can induce metal-to-insulator transitions caused by localisation of eigenstates [3]. Over the years, many other examples where found, from the emergence of sample specific mesoscopic current fluctuations [4] to the quantised Hall effect in two-dimensional electron gases [5].

INESC TEC (Institute for Systems and Computer Engineering, Technology and Science) is a private non-profit research institution, dedicated to scientific research and technological development, technology transfer, advanced consulting and training, and pre-incubation of new technology-based companies.

The Centre for Applied Photonics (CAP) is one of the 13 R&D Centres of INESC TEC. CAP performs R&D in applied photonics, principally focusing on optical fibre technology. CAP is oriented towards applied research and development in optical fibre sources, optical fibre communication, optical fibre sensors and microfabrication (thin films and integrated optics). In this session, you will discover CAP and some of the research being done in this centre.

Optical Analogues in Nematic liquid crystals

Tiago Ferreira, PhD Student

Light propagating in nonlinear optical materials, with local and nonlocal nonlinearities, brought the possibility of emulating quantum fluids in experimentally accessible setups. Indeed, a light beam propagating in these materials can be interpreted as a fluid, where the nonlinearity of the medium mediates the required interactions between the photons and the diffraction in the transverse plane to the propagation gives the effective mass of the fluid. This fluid interpretation has allowed the production of superfluid-like flows to emulate phenomena characteristic of these flows, such as drag-force cancelation or vortex nucleation, as well as the emulation of some gravitational phenomena. Such experiments can be performed with a variety of optical materials, however, at our research group, we have been exploring the possibility of using nematic liquid crystals, which are new in this context. Nematic liquid crystals are a nonlocal optical material that offers external mechanisms that can be used to tune their nonlinear response. This is done by applying an external electric field, and this property makes these materials very interesting for implementing optical analogues.

Vernier Effect: A Path for Giant Sensitivity

Paulo Robalinho, Research Assistant

The market for optical fiber sensors requires the study of new ultra-sensitive sensors with a wide range of applications in several areas of engineering. For this, the interest in developing more sensitive materials emerges, but it is not the only way to increase sensitivity. This presentation will be marked by the introduction of the Vernier effect in optical sensing. This effect consists in the measurement of the beat patterns that arise from the overlapping of different signals. Presently, its application allows colossal sensitivity, essential in sensors for micrometric and
nanometric scales.

Ultrafast Laser Micromachining and Applications in Optofluidics

João Maia, PhD Student

Ultrafast laser inscription is a versatile microfabrication technique capable of surface and volume processing of different classes of materials, such as glasses, crystals or polymers. In short, by tightly focusing a fs-laser beam inside a transparent medium, their high peak intensity can trigger a local modification in the structural properties of the material confined to a micrometric-sized volume. In fused silica, these modifications can be exploited to form either integrated optical devices or microfluidic systems or, owing to the confined nature of the laser-induced modification, optofluidic devices which combine both types of systems in a single substrate and in a user-defined three-dimensional architecture. This talk will present an overview of the work developed at INESC TEC concerning glass machining. Recent results on optical sensing based on a monolithic whispering-gallery mode resonator will also be presented.