Issue 1, 2014
Issue 1, 2013
No, it's not a moon passage in front of an exoplanet. It's a thin nematic film. Let me explain. Between condensed matter physics and chemistry, between solids and liquids, there is soft condensed matter. Soft condensed matter deals with the behavior of materials like gels, glasses, surfactants, or colloids. Typically these are fairly large molecules, possibly floating in some substrate, and can assemble to even larger structures....... [Read more]
Don't have time to read our 42-pages information brochure? We've put ourselves up to the task to summarize the most important...
Nordita Professor Alexander Balatsky has been awarded an ERC Advanced Grant to fund a five-year research project on Dirac...
In Finland there has been active discussions on political guidance of research (see eg. this article from the Finnish public...
The Nordic Physics Days will be held in Lund, June 12-14, 2013. The meeting, hosted by the Department of Physics at Lund...
Each year, Nordita recruits new post-docs and assistant professors from all over the world; see our staff list for names and...
No, it's not a moon passage in front of an exoplanet. It's a thin nematic film. Let me explain.
Image source: arXiv:1010.0832 [cond-mat.soft]
Between condensed matter physics and chemistry, between solids and liquids, there is soft condensed matter. Soft condensed matter deals with the behavior of materials like gels, glasses, surfactants, or colloids. Typically these are fairly large molecules, possibly floating in some substrate, and can assemble to even larger structures. Understanding this assembly, the existence of different phases, and also the motion of the molecules is mathematically challenging due to the complexity of the system.
But taking on this challenge is rewarding: Soft matter is all around you, from toothpaste over body lotion to salad dressing. It is even quite literally in your veins. One of the best known examples for soft matter however is probably not blood, but liquid crystals.
Liquid crystals are rod-like molecules whose chemical structure encourages them to collectively align. How well this works depends on variables in the environment, for example temperature and magnetic fields. Liquid crystal have different phases; the transition between them depends on these environmental variables. In the so-called nematic phase molecules are locally aligned but still free to move around, and the orientation might change over long distances.
To make the molecule orientations visible, one uses polarized light on a thin film of liquid crystals on some type of substrate and a polarization filter to take the image. The liquid crystal molecules change the polarization of the light depending on the molecules' orientation, so different light intensities become a measure for the orientation of the molecules.
For the images we are looking at here we have the substrate below the liquid crystal and air above it. These two different surfaces causes a conundrum for the molecules in the liquid crystal, because they would prefer to align parallel to the substrate, but vertical to the air surface. Now if the film is fairly thick - "thick" meaning a µm or more - the molecules manage to align along threads that bend to achieve this orientation, though there are the occasional topological defects in this arrangement, places where the molecules change orientation abruptly. This is what you see for example in the image below:
Picture Credits: Oleg Lavrentovich from the Liquid Crystal Institute at Kent State University.
For more pictures see here.
But this behavior changes if the film becomes very thin, down to a tenth of a ?m or so. Then, the competing boundary conditions from the two interfaces start getting in conflict with the molecules' desire to align, which breaks the symmetry in the plane of the liquid and leads to the formation of periodic structures, like the ones you see in the first image. In this example, the nematic film does not cover the whole area shown, but it's a drop that covers only the parts where you see the periodic structures. This has the merit that one can see that the orientation of the structure to the boundary is always perpendicular.
The typical molecules in these films are not very large. In the example here, it's 6CB with the chemical structure C19H21N. The size of this molecule is much smaller than the width of the film when the effect sets in, so this cannot be the relevant scale. The question at which width the instability sets in has been studied in this paper, where also the image was taken from. It's an intriguing effect that can teach us a lot about the behavior of these molecules, not to mention that it's pretty.
Our local nematic expert is Nordita postdoctoral fellow Oksana Manyuhina. Watch this video where Oksana explains her research in her own words.
Research Policies
In Finland there has been active discussions on political guidance of research (see eg. this article from the Finnish public broadcasting company, in Finnish; I will summarize the main idea with my own words).
Currently the Academy of Finland distributes about € 300 million of competitive research funding and about € 20 million based on programs that have been political priorities.
The current plans are that in the future, the Academy will get a new unit that will distribute about € 200 million on projects whose themes and priorities are set by the government. This will be competitive, but the topics should serve the priorities set by the government.
The Academy will continue to fund basic research with around € 300 million/year. The extra € 200 million will be mostly taken from basic funding for states research institutes (Finnish Meteorological Institute, Finland's Environmental Administration, and Geological Survey of Finland) as well as from Tekes (the Finnish Funding Agency for Technology and Innovation). This means that in the future states research institutes must compete for the funds that in the past have been used to run their operations. The rules for the competition are set partly so that they conform to the priorities of the government.
The Finnish government will also reserve € 30 million for research funding whose spending it will decide on its own.
The topic has crossed the news threshold to mainstream media due to polically motivated non-competitive funding (€ 700000) for celebrity philosopher (Pekka Himanen) whose researcher merits were found to be non-existent. Some feel that changes in funding schemes make such scandals more likely in the future. Personally I see good things as well as bad things in the proposal and I believe so do many other scientists. For sure those working in the above mentioned state research institutes do not like this, but for others having "more" competitive money around might not be that bad even if that is not for pure basic research. I do not have a firm opinion about this. Apparently in Sweden such funding already has a prominent role.
This is how Academy of Finland presents the proposed changes in its newsletter:
"... The other key proposal related to research is from an expert group appointed by the Finnish Government and deals with research institutes and funding. The aim is to implement a comprehensive overhaul of state research institutes by integrating them. A third pillar of funding subject to competition, a council for strategically targeted research, is proposed to be established alongside the funding instruments for scientific research and innovation. This instrument for strategically targeted research would fund problem-oriented research aimed at finding solutions to major societal challenges."
"According to the proposal, research funding subject to competition, supporting social policy and society's functions and services, would be marshalled under the strategic research funding instrument so that the funds available for strategic research funding would amount to EUR 200 million in 2016. Such funding would be collected from the state research institutes' research appropriations, from the Academy's programme-based research funding and from Tekes' innovation and research funding. Further, it is proposed that a council for strategically targeted research be established at the Academy be responsible for the management, decision-making and programme council structure for strategic research..."
Nordic Events
The Nordic Physics Days will be held in Lund, June 12-14, 2013. The meeting, hosted by the Department of Physics at Lund University in cooperation with the Nordic Physical Societies, starts at lunch time on the 12th of June and ends at lunch time on the 14th of June, and will consist of plenary lectures, parallel sessions and poster sessions. For more information and meeting program, see www.fysik.lu.se/npd2013.
This meeting, intended for both researchers and teachers in physics, is the third in a series of meetings in which the first was held in Copenhagen in 2009 and the second in Helsinki 2011.
Research Policies
Although Sweden is a leading scientific nation many other countries have seen greater progress during the last two decades as measured using bibliometric statistics. Several reports since the late 1990's have pointed out this pattern. This report from the Swedish Research Council 
aims to update the bibliometric statistics and identify potential explanations in the underlying bibliometric data. Thus, various subject fields, the degree of international collaboration, the degree of interdisciplinarity, publications in the foremost prestige journals and other aspects are scrutinised, The Swedish progress is compared with five other European countries; Denmark, Finland, Netherlands, Switzerland and the United Kingdom. All these, except Finland, are ranked ahead of Sweden when using several bibliometric indicators of scientific performance.
Some weak spots in the Swedish statistics are:
Research Policies
"The Academy of Finland has joined AcademiaNet with a view to facilitating the access of Finnish women to key positions in science and research. The AcademiaNet portal includes profiles and contact details of more than 1,000 leading female researchers from 24 countries, representing a total of 35 fields of research... AcademiaNet www.academia-net.org provides a helpful tool with an excellent database for people who want to find a suitable female candidate for leading academic and scientific positions or are looking for a scientific expert, committee member or conference speaker. Journalists will also find interesting interviewees for science articles..." [Read more...]
Interview
"The standard of physics research in Finland is high and covers most international lines of inquiry," says Professor Christian Enss, Chairman of the evaluation panel of physics research in Finland. However, it is important for physics research to reinvent itself and to pursue new emerging fields.
"Most international trends of physics research are well represented in Finland, and research topics are driven by researchers' own interests and curiosity. This is important because people work most effectively when they can work with subjects that interest them," says Professor Christian Enss, Chairman of the evaluation panel. [Read more...]
Research Evaluations
The quality of Finnish physics research is quite high and the research covers most major international trends. However, future funding support should especially be targeted at promoting the pursuit of emerging fields.
These are some of the conclusions drawn by an international panel of experts appointed by the Academy of Finland to evaluate physics research in Finland. [Read more...]
Science News
The Stellar Astrophysics Centre at Aarhus University is part of an international research group that recently announced in Nature the discovery of a new exoplanet, circling a star 212 lightyears away from Denmark. About the size of our Moon, Kepler Planet 37b is the smallest planet discovered since the observation of the first exoplanet in 1989.
Science News
Using methods from string theory, researches at the Niels Bohr Institute have uncovered new surprising properties of black holes resembling hydrodynamic and piezoelectric phenomena, according to a paper in PRL.
Application Calls
In Vetenskapsrådets (VR) yearly call the two grants of interest for physicists are 'Project research grants' and for young researchers, seven or less years since PhD: 'Project grants for young researchers'.
Application Calls
Research Evaluations
The Academy of Finland report reviews the state and position of the Finnish research system in international comparison as well as the strengths of different scientific disciplines and areas in need of further development. [Read more...]
Winter receding around the Nordita buildings
Nordita Professor Alexander Balatsky has been awarded an ERC Advanced Grant to fund a five-year research project on Dirac Materials starting in April 2013.
The ERC Advanced Grant funding scheme targets exceptional research leaders across all fields of science and enables them to pursue frontier research of their own choice.
This is the second ERC Advanced Grant to go to Nordita: in 2008 the Astrophysical Dynamo project of Axel Brandenburg was awarded a five-year grant.
The elegant Dirac equation, describing the linear dispersion (energy/momentum) relation of electrons at relativistic speeds, has profound consequences such as the prediction of antiparticles, reflection less tunneling (Klein paradox) and others. The recent discovery of graphene and topological insulators highlights the scientific importance and technological promise of materials with "relativistic Dirac dispersion" of electrons for functional materials and device applications. The term "Dirac materials" encompasses a subset of (materials) systems in which the low energy phase space for fermion excitations is reduced compared to conventional band structure predictions (i.e. point or lines of nodes vs. full Fermi Surface).
The aim of the ERC funded project is to use the sensitivity of nodes in the electron spectrum of Dirac materials to induce controlled modifications of the Dirac points/lines via band structure engineering in artificial structures and molecular devices, via scattering processes and controlled doping. This research will expand our theoretical understanding and guide design of materials and engineered geometries that allow tunable energy profiles of Dirac carriers.
Yasser Roudi with Royal Norwegian Society of Sciences and Letters praeses Professor Kristian Fossheim
Photo: Per Osland
On 8 March, the Royal Norwegian Society of Sciences and Letters announced that Nordita Corresponding Fellow Yasser Roudi is the 2013 recipient of the Society's scientific award for young researchers (IK Lykke Fund). [Read more...]
Yasser was a Fellow at Nordita from 2008 to 2010 after which he moved to take up a faculty position at the Kavli Institute in Trondheim while also being a Corresponding Fellow at Nordita. Before moving to Stockholm, Yasser studied physics at Sharif University of Technology in Tehran where he completed his Bachelors at the age of 20. He then moved to do his PhD at the International School of Advanced Studies (SISSA) in Trieste, the youngest in the institute's history. He defended his doctorate in 2005 as a 24-year-old and then became a senior research fellow at the Gatsby Unit, University College London. He has been awarded the Bogue Research Fellowship in 2008 to work at Cornell University and the Burgen Scholarship in 2012 by Academea Europea. Yasser's main research interest is understanding information processing in living organisms and machines using tools form statistical mechanics.
Applications are invited for a tenured Senior Lecturer position in Theoretical High-Energy Physics at the Department of Physics and Astronomy at Uppsala University. During the first five years of the appointment the holder of the position will work 50% at Uppsala University and 50% at Nordita, the Nordic Institute for Theoretical Physics, in Stockholm and after that period work full-time at Uppsala University. The holder of the position is expected to spend equal time at both institutes during the five-year period.
The application deadline is May 20. The announcements and the details of the application procedure can be found on the Nordita Open Positions page as well as on the Nordita front page.
Nordita will host three new PhD positions:
The announcements and the details of the application procedure can be found on the Nordita Open Positions page as well as on the Nordita front page.
Five new Nordita Fellowships have been awarded to
There were 331 applications this year. They were evaluated and ranked by the three Nordic Research Committees and by the Nordita faculty. We would like to take this opportunity to thank committee members for their time and commitment to Nordita. The new Nordita Fellows will arrive in September and October 2013.
Cecilia Rorai
Astrophysics and Condensed Matter Physics
Cecilia received her PhD in January 2012 from the University of Maryland and the University of Trieste, for work on "Vortex Reconnection in Superfluid Helium" under the guidance of Michael E. Fisher, Daniel P. Lathrop, and K. R. Sreenivasan. Following her PhD studies she was a postdoctoral fellow at National Center of Atmospheric Research, Boulder, Colorado. She joined Nordita in March 2013 as a postdoctoral fellow working on a VR sponsored project to study the nature of turbulence in complex fluids. At Nordita Cecilia plans to work in close collaboration with D. Mitra (Nordita) and L. Brandt (KTH, Mechanics).
Stanislav Borysov
Condensed Matter Physics
Stanislav received his PhD in theoretical physics at the Institute of Applied Physics of National Academic of Science of Ukraine in 2011; the subject was statistical analysis of complex systems and hierarchical structures using non-Gaussian power-law distributions. After that he worked at Samsung Electronics as a researcher and software engineer. In 2012 he became a postdoc at KTH/Nordita. The current research interests of Stanislav are nonlinear problems in atomic force microscopy and applying machine learning tools to the search of new materials based on first principles calculations.
Illa R. Losada
Astrophysics
Illa started her PhD studies in January after concluding her masters degree at the Instituto de Astrofísica de Canarias (IAC). At Nordita Illa will work within the VR-supported project on the "Formation of active regions in the Sun", where the goal is to develop the foundations of a radically new suggestion for the formation of active regions in the Sun, based on the recent detection of an instability of strongly stratified turbulence in the presence of a weak magnetic field, which is now called the negative effective magnetic pressure instability (NEMPI). Illa already visited Nordita in May and November to work on the NEMPI effect.
Ahmet Devlen
Astrophysics
Ahmet received his PhD from the University of Ege in 2001, where he has been an Assistant Professor since 2003. In March 2013 he joined Nordita as visiting scientist. Ahmet is working in the field of variable stars and eclipsing variables, Algols and semi-regular variables. He conducts photometric and spectroscopic observations of variable stars and is analyzing their light curves, investigating period changes and magnetic activity. He is interested in the structure of accretion disks in the binaries, the magnetic activity cycle periods of Algol stars, nondimensional parameterizations of dynamo and activity quantities, and the development of theoretical models of light curves of Algol systems with accretion discs.
After spending a year and a half at the University of Helsinki, Visiting Professor Matthias Rheinhardt returned to Nordita in February. One of his main research projects is the fully nonlinear test-field method for computing the full set of turbulent transport coefficients in the Navier-Stokes and continuity equations, which he hopes to finish soon. This method allows the computation of the turbulent viscosity tensor, as well as related effects such as the so-called anisotropic kinetic alpha effect and the Lambda effect. The test-field method is a general approach to characterizing simulation results and to obtain turbulent transport coefficients that describe its large-scale properties. Examples include the test-field method for magnetic fields and for passive scalars, where Matthias has made important contributions in the past. Matthias also contributes to other activities within the astrophysics group at Nordita, such as investigating the suppression of turbulent convective energy transport by magnetic fields and the possibility of an instability, which might be responsible for producing sunspots. His stay at Nordita is supported through the ERC AstroDyn grant.
Professor Michael Liberman of the Department of Physics and Astronomy at Uppsala University will be making regular visits to the astrophysics group at Nordita for research collaboration during 2013 and 2014. Michael's work covers a wide range of aspects of turbulence including the theoretical and numerical study of the tangling clustering instability of small particles in temperature-stratified turbulence, its impact on raindrops formation and its influence on combustion performance. Turbulent combustion is a topic of interest to Nordita and was also to topic of a Program on Combustion in 2010. The classical combustion paradigm is based on and implies to large extend the use of a simplified one-step global chemical reaction model. Even though a considerable progress has been achieved in qualitative understanding of the combustion physics, the model does not provide quantitatively correct results necessary for practical use, and can be even qualitatively incorrect especially the case of non-stationary processes. It is not surprising that current combustion modeling tools are insufficiently accurate and do not cope with modern demands and standards for environment from engine manufactures.
Michael is now focusing on the fundamental study of combustion processes for the development of new technologies for more efficient and cleaner use of hydrocarbon fuels and for the improvement of combustion safety, related to the use and/or storage of highly reactive mixtures (hydrogen safety). His work includes both theoretical and analytical study, high performance numerical simulations of a wide diversity of combustion processes and the development of methods and technological solutions with improved efficiency of energy production of the processes involving combustion of fossil fuel, and stabilized lean combustion for reduced emissions. His work also aims at the theoretical study of gas-discharge plasma-stimulated activation of combustion of fuel-air mixtures to identify ways of actively controlling the rate of combustion of air-fuel mixtures by reducing the time of ignition to increase the burning rate and to reduce harmful emissions.
Koen Kemel, Fabio Del Sordo, and Simon Candelaresi, the three PhD students who started back in February 2009 (see Nordita Newsletter 2009, issue 1) and who defended their PhD theses last fall (see the Nordita Newsletter 2012, issues 3 and 4), have now left to take up post-doc positions.
Koen started in the plasma-astrophysics Section of the Katholieke Universiteit Leuven, and, early Summer, Fabio will start at CEA/Saclay to work on star formation while Simon will start at the University of Dundee to work on solar magnetohydrodynamics.
Holographer Alessandera Cagnazzo was a Visiting Postdoctoral Fellow at Nordita for one year, and has now taken up a position at DESY in Hamburg.
We would like to take this opportunity to thank all these young scientists for their time at Nordita and for their contribution to the vitality of the institute. They have our best wishes for their future careers.
Each year, Nordita recruits new post-docs and assistant professors from all over the world; see our staff list for names and their fields of interest.
They are keen to become more familiar with the work done in the Nordic countries and would appreciate being invited for a seminar or a colloquium. Nordita has allocated funds to reimburse their expenses.
Many of our staff have placed links to their talks on their individual home pages; see, e.g., Alexander Balatsky, Axel Brandenburg, Oliver Gressel, Sabine Hossenfelder, Dhrubaditya Mitra, Christopher Pethick, Stephen Powell, Dmytro Volin, Jörn Warnecke.
Nordita has entered into cooperation agreements with the International Centre for Theoretical Physics (ICTP) in Trieste, Italy, the Aalto Science Institute (AScI) in Espoo, Finland, and the South American Institute for Fundamental Research (SAIFR) in São Paulo, Brazil.
These agreements promote scientific collaboration and facilitate the exchange of visitors. Nordita will also be co-sponsoring several workshops with our partners this year.
Don't have time to read our 42-pages information brochure? We've put ourselves up to the task to summarize the most important facts about Nordita in 5 Minutes. That wasn't easy. But today we're happy to tell you that the result is now available on YouTube.
Some short videos about researchers here at Nordita and their work will appear in the soon future. In this issue's Feature article you can watch Oksana explain the fascinating world of liquid crystals. We hope that these short videos will give you an impression of our institute in particular, but also of research in theoretical physics in general.
GalileoMobile is an itinerant non-profit educational project that aims to bring astronomy to everyone, especially children and young people in places that have had little access or no contact at all with science education. The goal of the project is to promote awareness and interest in learning about the Universe, and through projects like this, one can convey the idea to all of us who live "under the same sky" that science can be fascinating if can share it and learn it in a fun way.
As mentioned on the homepage of UNAWE (EU Universe Awareness Project), Nordita supports this important initiative both financially and by way of the participation of Fabio Del Sordo, onetime PhD student at Nordita, in the first GalileoMobile trip to the Andean Altiplano in 2009. In the words of the director of Nordita, Professor Lárus Thorlacius,
"Nordita supports a number of outreach activities and we are happy to assist the GalileoMobile project to stimulate young minds and bring the wonders of astronomy to a new generation".
This spring Fabio will take part in a GalileoMobile tour in Nepal.
The 2013/2 issue of Finnish popular science magazine "Tähdet ja avaruus" ("Stars and Space") has an article (in Finnish) on Quantum Gravity, as seen through the eyes of Sabine Hossenfelder, assistant professor at Nordita, and Renate Loll and Robert Brandenberger, who all took part in the Nordita program "Perspectives of Fundamental Cosmology" in November last year.
The title of the article, written by Laura Koponen, is "The Theory of Everything is Waiting for its Discovery", and in her interview Sabine reflects on how theory yields to experience.
→ See List of all Nordita Events: www.nordita.org/events
Program
8 April — 3 May 2013
The goal of the programme is to advance our understanding of the physical processes generating differential rotation in various types of stars, and the role that this effect plays for stellar magnetic activity and dynamos. The Sun is the only star for which the internal rotation profile is observationally known thanks to helioseismology – for other stars, only the surface differential rotation can be inferred from photometric or spectroscopic observations. The main goal of the program is to investigate the connection between the theories and observations and obtain better understanding of the generation and role of differential rotation for stellar magnetism.
Coordinators: Rainer Arlt, Petri Käpylä, Maarit Mantere
Program
6—31 May 2013
Stability and transition of flows belong to fundamental issues in the field of fluid mechanics. Predicting flow structures and characteristics requires deep understanding of the different routes of transition. Further, similarities between the fluid behavior (instabilities) and different phenomena within the field of astrophysics give an opportunity to explain some of astrophysical phenomena based on the stability characteristics of canonical shear flows.
Coordinators: Rama Govindarajan, Jens N. Sørensen, Luca Brandt, Dan Henningson, Shervin Bagheri, Ardeshir Hanifi
Workshop
22—25 May 2013
The meeting addresses applications of statistical mechanics to biological cooperativity on all level from the molecular to strategical actions and the development of populations. The workshop is held in Mariehamn, Åland.
Coordinators: Juho Rousu, Ralf Eichhorn, Mikko Alava, Erik Aurell
Workshop
27—29 May 2013
Writing about science for the public is challenging. With deadlines looming, it's hard to carve out time to recharge your intellectual batteries, find distinctive stories, and get a broad overview of where researchers are headed. We've designed this workshop to give you the background material you need to cover astrophysics and cosmology, packing as much as possible into as short a time as possible for the busy working journalist.
Coordinators: Sabine Hossenfelder, George Musser
Workshop
3—5 June 2013
This workshop will focus on highlights of materials and engineering capabilities at Los Alamos, KTH and Nordita in the field of complex materials that are of great scientific interest for basic science and for nuclear energy applications. From the perspective of basic science we will discuss strong electronic correlations along with strong coupling to multiple degrees of freedom. The workshop will also discuss our current understanding of the interactions of defects at interfaces in materials subjected to extreme radiation doses and mechanical stress in order to synthesize new interface-dominated materials with tailored response under such extreme conditions.
Coordinators: Avadh Saxena, Stephen Powell, Anders Rosengren, John Hertz, Alexander Balatsky
Program
3—28 June 2013
This programme brings together astrophysical theoreticians and simulators interested in radiative feedback, specifically the dynamical effects of radiative heating of dense gaseous structures, a process known as photo-evaporation, which occurs in regions of intense star formation, in the dense planet forming discs around young stars, in massive planets orbiting close to their parent star and even in the earliest phases of galaxy formation in the Universe. As part of the programme a 5-day workshop will address the latest observational and theoretical results.
Coordinators: James Owen, Andreas Burkert, Barbara Ercolano, Garrelt Mellema
Workshop
10—14 June 2013
In order to further reduce the cost of whole-genome sequencing, radically new methods need to be developed to determine the nucleobase order in DNA. Electronic sequencing could potentially provide an attractive alternative to the existing biochemical approaches. At this workshop, leading experts in the field will discuss the science and technology underpinning various forms of electronic sequencing including nanopore-based ionic conductance measurements, embedded electrodes, and STM-based techniques.
Coordinators: Dmitry A. Yarotski, Rodrigo G. Amorim, Ralph Scheicher, Alexander Balatsky
Program
1—27 July 2013
The 14 TeV LHC will look further above the electroweak scale, but where do we go beyond that to improve our understanding of the fundamental constituents of the Universe? Should we look to the results of a high-luminosity SLHC or a higher energy VLHC, do we need a precision linear collider at ILC or CLIC energies, are neutrino or flavour experiments essential to move forward, what can we learn from astrophysics?
Coordinators: Paolo Di Vecchia, Per Osland, Are Raklev
→ See Current Open Postitions: www.nordita.org/positions
