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Steady-state currents through nanodevices: a scattering-states numerical renormalization-group approach to open
1Institut für Theoretische Physik, Universität Bremen, P.O. Box 330 440, D-28334 Bremen, Germany.
Physical Review Letters
|September 4, 2008
Summary
We present a numerical renormalization group (NRG) method for calculating steady-state currents in nanodevices. This approach accurately models open quantum systems and electron interactions, enabling conductance calculations under various conditions.
Area of Science:
- Quantum physics
- Condensed matter physics
- Nanotechnology
Background:
- Understanding steady-state currents in nanodevices is crucial for quantum electronics.
- Modeling open quantum systems requires accurate boundary conditions.
- Electron-electron interactions significantly impact nanodevice properties.
Purpose of the Study:
- To develop a numerical renormalization group (NRG) approach for calculating steady-state currents in nanodevices.
- To incorporate boundary conditions for open quantum systems via scattering-states continuum discretization.
- To investigate the effects of interactions and external fields on transport properties.
Main Methods:
- Discretization of the scattering-states continuum.
- Introduction of two degenerate Wilson chains for left- and right-moving electrons.
- Application of time-dependent NRG to evolve density operators.
- Calculation of differential conductance as a function of bias voltage (V), temperature (T), and magnetic field.
Main Results:
- The proposed NRG approach correctly handles boundary conditions for open quantum systems.
- The method accounts for time-reversal symmetry in the absence of bias.
- Successful evolution of density operators from noninteracting to interacting regimes.
- Differential conductance is calculated for varying V, T, and magnetic fields.
Conclusions:
- The numerical renormalization group (NRG) method provides a robust framework for studying steady-state currents in nanodevices.
- This approach accurately captures the physics of interacting electrons in open quantum systems.
- The method is versatile for investigating the influence of bias, temperature, and magnetic fields on quantum transport.
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