Home > Research
In spotlight

kibble_small.jpg29. 12. 2014
Light control over topological charge in nematic liquid crystals

Authors M. Nikkhou, M. Škarabot, S. Čopar, M. Ravnik, S. Žumer and I. Muševič from Jožef Stefan Institute and Faculty of Mathematics and Physics (FMP), University of Ljubljana, have just reported on the discovery of light-control of the topological charge in the system of confined nematic liquid crystals. In the paper Light-controlled topological charge in a nematic liquid crystal, just published in the journal Nature Physics, they demonstrate that the confinement of space, specifically with microscopic colloidal fibres, affects the later stages of the Kibble-Zurek mechanism which allows for trapping and control of topological defect loops with different values of the topological charge. By using laser tweezers, they show that the dynamics of topologically charged objects can be well manipulated, including processes of repulsion and annihilation. The structure of ordering fields and the annihilation dynamics were determined also with intensive numerical modelling, using computer clusters which run at FMP. More generally, the demonstrated research reveals the sensitivity of the Kibble-Zurek mechanism on the connectedness of space and symmetry-breaking boundary conditions and further provides a new insight into key topological invariants of general topologically conditioned ordering fields.

The Faculty of Mathematics and Physics works in close collaboration with the following institutions in Slovenia:

Research fields
The Department of Mathematics’ research is strongly connected to the work of the Institute of Mathematics, Physics and Mechanics.  Our members are active in 17 fields of research.
Each and every lecturer and assistant is involved in research.  Members of the Department of Physics head research groups at the Department and at the institutes.
This week
Numerical analysis seminar Karla Ferjančič: Konstrukcija G^3 racionalnega gibanja stopnje osem Sreda, 4.3.2015, od 10h do 12h, soba 3.06 na Jadranski 21
Astrodebate Prof. Maruša Bradač: Dark Matter and First Galaxies Light Up Prof. Maruša Bradač bo imela predavanje na Ponedeljkovem fizikalnem kolokviju v ponedeljek, 2. ...
Complex analysis seminar Uroš Kuzman: Konstrukcija J-holomorfnega diska pripetega na torus Torek, 03.03.2015 ob 12:30, soba 3.06 na Jadranski 21
Seminar for history of mathematical sciences Jurij Kovič: Kratka zgodovina perspektive in njene povezave z geometrijo Ponedeljek 2. 3. 2015, Plemljev seminar, 14.15-16.00

COST Workshop on Modelling of Flowing Matter
16 - 18 February, Faculty of Mathematics and Physics, University of Ljubljana, Slovenia


Physics of Complex Colloids
14 - 18 May 2013, Cankarjev dom, Ljubljana


Workshop on assembling of superstructures in soft matter
11 - 13 October 2012, Klub Cankarjevega doma, Cankarjev dom, Ljubljana


24 - 26 October 2012, "Jožef Stefan" Institute


Relativistic Positioning Systems and their Scientific Applications 
19 - 21 September 2012, Brdo pri Kranju, Slovenija


Ljubljana Physics Summit 2012
March 3, 2012, "Jožef Stefan" Institute


COINAPO Topical Meeting:
Composites of nanotubes and polymers:
joining theoretical modeling with experimental investigations
8 - 9 December 2011, Ljubljana, Slovenija


Physics in Ljubljana
17 - 24 July 2011, Ljubljana, Slovenia


Confined Liquid Crystals: Landmarks and Perspectives

19 - 20 July 2010, Ljubljana, Slovenija


19 - 21 October 2009, National Institute of Chemistry, Ljubljana, Slovenija


ESF Research Conferences
Self-assembly of guanosine derivatives: from biological systems to nanotechnological applications
20 - 25 June 2009, Obergurgl, Austria


4th European school in Material Sciences
Mechanical Properties of Complex Metallic Alloys
25 - 30 May 2009, MONS Hotel and Congress Centre, Ljubljana, Slovenija


ESF Workshop
Towards single-spin physics
November 30, 2007, MONS Congress Center (Ravnikar room), Ljubljana, Slovenija
programme (pdf, 191 kb)


10 - 12 October 2007, Jožef Stefan Institute, Ljubljana, Slovenija








7th European Symposium for the Protection of the Night Sky
Light Pollution and Global Warming
International Exhibition: Quality Lighting and Light Pollution
5 - 6 October 2007, Bled, Slovenija



International Liquid Crystal Elastomer Conference
27 - 29 September 2007, Ljubljana, Slovenija


Fundamentals of Nanoelectronics
2 - 7 September 2007, Portorož, Slovenija