• Theoretical Condensed-Matter Physics
• Theoretical Elementary Particle Physics
• Astrophysics and General Relativity
• Experimental Elementary Particle Physics
• Accelerator Physics
• Experimental Condensed-Matter Physics
• Biological Physics
• Multidisciplinary Research
• Major Research Facilities
• Resources for Researchers

M.Sc., Physics, 1993, Leiden University. M.Sc., Mathematics, 1994, Leiden University. Ph.D., 1997, Leiden University. Postdoctoral fellowship, Harvard University, 1997-1999. Assistant Professor, Physics, Cornell University, 1999-2003. Associate Professor, Physics, Cornell University 2003- 2008. Professor, Physics, Cornell University, 2009-present. Professor, Freie Universitaet Berlin, 2009-present.Alfred P. Sloan Fellow, 2000-2001. Packard Fellow 2001-2006. Humboldt Foundation Bessel Award, 2006. Provost's Award for Distinguished Scholarship, 2007. Humboldt Foundation Humboldt Professorship, 2008.

Research Areas
Theoretical mesoscopic physics, in particular theory of quantum transport in mesoscale systems; physics of disordered electron systems; quantum chaos; random-matrix theory

Current Research

My research interests are in the field of theoretical mesocopic physics. Mesoscopic physics is a subfield of condensed matter physics that deals with the properties of small, mostly electronic systems, which are governed by the interplay of quantum mechanics and scattering by impurities or boundaries. Examples of such systems are semiconductor or metal wires, small metal grains, or semiconductor quantum dots. Similar physics also occurs for systems with multiple scattering of microwaves or light.

Questions of recent interest have been: What is the effect of Coulomb interactions in a quantum dot (a small metallic particle coupled to the outside world via point contacts) if the coupling between the quantum dot and source and drain electrodes is strong? What is the size-dependence of quantum-interference corrections to transport through quantum dots if the electron motion inside the quantum dot is ballistic?

Another topic of interest is magnetism on the nanoscale. My research addresses the effects of the spin-transfer torque, as well as consequences of quantum phase coherence and impurity scattering in nm-sized magnets. The research on spin-transfer torque effects is done in close collaboration with the Ralph and Buhrman groups.

Graduate Students
Joern Kupferschmidt

Postdoc
Jens Bardarson

Spotlight

Yan-Jiun Chen is a graduate student working with Professor Jim Sethna studying non-equilibrium statistical physics, in particular, the scaling properties of crackling noise in magnets.  As a magnet is magnetized, magnetic spins flip in avalanches of all different sizes, this is called the Barkhausen effect (or crackling noise). The properties of these avalanches exhibit self-similarity, and can be studied using powerful theoretical tools in the form of the renormalization group (RG).  This means that studying these avalanches can tell us ...
read more