Physical Chemistry Seminar: Green’s function methods for single molecule junctions

Abstract:

We discuss theoretical Green’s function methods applicable to open quantum system, in general, and single molecule junctions, in particular. Two characteristic energy scales governing the physics are many-body interactions within the junctions and molecule–contact coupling. We, therefore, identify weak interactions and weak coupling as two limits that can be conveniently treated within, respectively, the standard nonequilibrium Green’s function (NEGF) method and its many-body flavors: pseudoparticle and Hubbard NEGF. Finally, the intermediate regime, where the two energy scales are comparable, can in many cases be efficiently treated within the nonequilibrium dual approaches. After general overview of the methods we focus on new insights the methods provide in the areas traditionally teated within wave-function or density matrix based approaches. In particular, we discuss Green’s function perspective on optoelectronics, molecular dynamics, and quantum thermodynamics. 

Seminar Organizer: Prof. Guy Cohen