Dec 12 – 17, 2010
Europe/Stockholm timezone
This second part of the program will run: December 12 - 17, 2010. The classical theories on phase transitions are based on the thermodynamic limit. This implies infinitely large or small extension on all the systems that are considered. The success of the resulting scaling laws and the corresponding generalisation is impressive. However, these theories fail to address many of the important aspects, as finiteness in extension is apparent in most physical systems.   As an example, the physics of magnetic multilayers has caused considerable attention lately, largely due to their technological importance. This interest has implied substantial increase in our knowledge and triggered renewed views on e.g. the range of the magnetic interactions. Interactions over large distances are now integrated in the description of the ordering of such systems.   In classical Monte Carlo calculations the interactions are most frequently mapped onto nearest neighbours. This has been shown to yield a correct behaviour for infinite systems, thus there has been limited driving force to use more complicated models (and CPU intensive) in this type of studies. However, this approach will not hold for finite systems with long-range interactions. Obtaining better understanding of phase transitions of confined systems is not only timely, it will enhance our understanding of dimensional crossovers, as well as the changes in the critical parameters.   These effects are not limited to magnetic phase transitions. Any second order transition, with corresponding fluctuations is expected to show strong finite size effects, on ordering temperature as well as the critical exponents. Thus, this question is of highly generic nature and has significance within condensed matter physics, chemistry as well as biology. In this second half of the program, we will start with readdress the influence of one dimensional confinement. Thereafter we will focus on the effect of lateral confinement on magnetic ordering and finally, we will address the influence of dipolar interaction on the collective behaviour. Special attention will be given to artificial spin ice, both ground state properties and excitations.