Microscopic theory and simulation of electronic quantum nanodevices

Supervisor: Fausto Rossi

The primary goal of this thesis work is the microscopic description of electronic dissipation and decoherence phenomena in state-of-the-art quantum materials and related nanodevices (see, e.g., Ref[1]).

The continuous progress in nanophysics and related nanotechnologies pushes device dimensions toward space- and/or time-scales where the semiclassical or Boltzmann theory is no longer applicable, and genuine quantum approaches are needed. To this aim, during the last decades a number of simplified quantum treatments have been proposed and routinely employed. The latter are typically grounded on a hybrid combination between a fully quantum-mechanical treatment of the deterministic carrier dynamics and a semiclassical treatment of dissipation and decoherence phenomena.

However, as recently pointed out (see, e.g., Ref.[2]), such hybrid treatments may lead to anomalous/unphysical results.Aim of the proposed research activity is the development of fully quantum-mechanical dissipation and decoherence models able to overcome the limitations of the simplified quantum simulation schemes just recalled, thus providing a correct description of the highly non-trivial interplay between electronic phase coherence and dissipation/decoherence in novel nanomaterials and related devices.  

References

[1] F. Rossi, Theory of Semiconductor Quantum Devices (Springer, 2011)

[2] R.C. Iotti et al., Phys. Rev. B96, 115420 (2017)