Dr. Daniel Urban  
Physikalisches Institut Email: daniel.urban@iwm.fraunhofer.de


Research Topics  
My research interests are within the field of electron transport in nanostructures.
When the system size approaches the nano scale, quantum mechanical effects become important and start to dominate over
the ''classical physics'' that we are custom with from everyday life.
Besides a fundamental interest in these quantum phenomena they are foreseen to become essential to prospective
nanoelectronic devices and fundamental to a possible realization of a quantum computer in the future.
During my PhD I examined metallic nanowires, 3dimensional wires with a diameter of only a few atoms thickness. The remarkable stability of these ''ultimate'' conductors turned out to be due to a particular electronic shell filling, an archetype of a quantum size effect. With a comprehensive stability analysis we could relate the experimentally observed quantized conductance values with the energetically favourable geometric configurations of the nanowires and shed light on their interplay with symmetry breaking deformations and scaling laws. Subsequently I started to study the noise properties of mesoscopic conductors. Current and charge fluctuations contain various informations on the system and the underlying interactions. Since the higher order moments of the distribution of transmitted charges through a conductor are small and hard to observe experimentally, effective detectors have to be designed and respective theoretical models have to be developed. Here I worked on the theory of the Josephson junction threshold detector and on the problem of heating effect through phonons on the full counting statistics of a molecular junction or atomic wire. In parallel, I recently started the study of two dimensional lattice systems which can be described by a Diraclike equation of a pseudo spin 1. These lattices are in some respect similar to graphene (described by a pseudospin 1/2 Dirac equation) but generalize this concept to the realm of integer spin and show a number of new and interesting aspects. We investigate these lattices also in the perspective of the emergence of topological states of matter. My current line of research includes


Publications  


Curriculum Vitae  
1994  Abitur at the Hochrheingymnasium (highschool) in Waldshut  
1994  1999  Studies of physics at the University of Freiburg  
1997  2002  Fellowship of the Studienstiftung des deutschen Volkes  
1997  1998  Studies of physics at the Université Paris Sud XI, Orsay  
1997  1998  Fellowship of the Dr. Jürgen Ulderup Foundation  
2001  2002  Diplomathesis in the theoretical solid state physics group of Prof. H. Grabert Subject: Stability analysis of metallic nanowires 

2003  GustavMieAward of the University of Freiburg for the best Diplomathesis 2002  
2002  2006  PhD studies in the theoretical solid state physics group of Prof. H. Grabert Subject: Stability, Symmetry Breaking, and Scaling Properties of Metallic Nanowires 

2002  2006  Associate member of the EU research and training network DIENOW  
23/2004  1st research stay at the Department of Physics, University of Arizona, USA  
23/2005  2nd research stay at the Department of Physics, University of Arizona, USA  
2006  present  Postdoctoral Research Associate at the AlbertLudwig University Freiburg  
2008  Pfizer Award for young researchers  
29/2009  Research stay at the Universidad Autonoma de Madrid, Spain  