Electronic phase coherence versus dissipation in solid-state quantum devices: Two approximations are better than one

Abstract

In the microscopic modeling of new-generation electronic quantum nanodevices a variety of simulation strategies have been proposed and employed. Aim of this Letter is to point out virtues versus intrinsic limitations of non-Markovian density-matrix approaches; we shall show that the usual mean-field treatment may lead to highly unphysical results, like negative distribution probabilities and non-dissipative behaviours, which are particularly severe in zero-dimensional electronic systems coupled to dispersionless phonon modes. This is in striking contrast with Markovian treatments, where a proper combination of adiabatic limit and mean-field schemes guarantees a physically acceptable solution; as a result, the unusual conclusion is that two approximations are better than one.

6 pages, 6 figures

References in corpus (3)

• Polaron relaxation in self-assembled quantum dots: Breakdown of the semi-classical model
• Derivation of nonlinear single-particle equations via many-body Lindblad superoperators: A density-matrix approach
• Comparison between a quantum kinetic theory of spin transfer dynamics in Mn doped bulk semiconductors and its Markov limit for non-zero Mn magnetization

Cited by in corpus (3)

• Optoelectronic device simulations based on macroscopic Maxwell-Bloch equations
• Density matrix Monte Carlo modeling of quantum cascade lasers
• Quantum dissipation with conditional wave functions: Application to the realistic simulation of nanoscale electron devices