A time-dependent approach to electron pumping in open quantum systems

Abstract

We propose a time-dependent approach to investigate the motion of electrons in quantum pump device configurations. The occupied one-particle states are propagated in real time and used to calculate the local electron density and current. An advantage of the present computational scheme is that the same computational effort is required to simulate monochromatic, polychromatic and nonperiodic drivings. Furthermore, initial state dependence and history effects are naturally accounted for. This approach can also be embedded in the framework of time-dependent density functional theory to include electron-electron interactions. In the special case of periodic drivings we combine the Floquet theory with nonequilibrium Green's functions and obtain a general expression for the pumped current in terms of inelastic transmission probabilities. This latter result is used for benchmarking our propagation scheme in the long-time limit. Finally, we discuss the limitations of Floquet-based schemes and suggest our approach as a possible way to go beyond them.

14 pages, 8 figures

References in corpus (10)

• Driven quantum transport on the nanoscale
• Dictionary between scattering matrix and Keldysh formalisms for quantum transport driven by time-periodic fields
• Optimal Control of Quantum Rings by Terahertz Laser Pulses
• Approach to steady state transport in nanoscale conductors
• Bound states in ab initio approaches to quantum transport: A time-dependent formulation
• Microscopic Current Dynamics in Nanoscale Junctions
• Ab initio simulations of excited carrier dynamics in carbon nanotubes
• Transient regime in non-linear transport through many-level quantum dots
• Photovoltaic and Rectification Currents in Quantum Dots
• Non-adiabatic transport in a quantum dot turnstile

Cited by in corpus (4)

• Spin-flip scattering in time-dependent transport through a quantum dot: Enhanced spin-current and inverse tunneling magnetoresistance
• The Role of Bound States in Time-Dependent Quantum Transport
• AC transport in carbon-based devices: challenges and perspectives
• Lanczos-adapted time evolution for open boundary quantum transport