Dr. Dragos Anghel visits the department and Ionel Tifrea for a week between APS meetings. 

Dragos is a condensed matter theorest from Horia Hulubei National Institute of Physics and Nuclear Engineering IFIN HH in Bucharest working to develop advanced quantum and statistical applications of materials and nanoscience especially for the construction of ultrasensitive devices.

His colloquium described his recent contributions to the field of fractional exclusion statistics (FES), introduced by Haldane.

The statistical properties of FES systems have been calculated independently by several practitioners by a variety of methods. FES has been observed in several types of systems, including quasiparticle excitations, the fractional quantum Hall effect, quantum antiferomagnets, Bose and Fermi systems, excitations or motifs of spins on spin chains, and elementary volumes obtained by coarse-graining in the phase space of a system.

Recently, a stochastic method for the simulation of the time evolution of FES systems has been introduced and the general FES formalism amended to include the change of the FES parameters with a change of the particle species. This amendment has allowed Dragos in several recent publications to describe general interacting particle systems as ideal systems which obey FES.

For his colloquium, Dragos explained the concept of FES and its basic properties and presented applications. He thus focused on the general procedure by which interacting particle systems can be described as ideal FES gases.

Dragos, it was great meeting you and visiting with you over the course of the week. We found your very pleasant demeanor a shining example of your webpage motto: The only disability is a bad attitude!  

Dragos (left) with his group in BucharestDragos (left) with his group in Bucharest