Applicability of the Wide-Band Limit in DFT-Based Molecular Transport Calculations

Abstract

Transport properties of molecular junctions are notoriously expensive to calculate with ab initio methods, primarily due to the semi-infinite electrodes. This has led to the introduction of different approximation schemes for the electrodes. For the most popular metals used in experiments, such as gold, the wide-band limit (WBL) is a particularly efficient choice. In this paper we investigate the performance of different WBL schemes relative to more sophisticated approaches including the fully self-consistent non-equilibrium Green's function (NEGF) method. We find reasonably good agreement between all schemes for systems in which the molecule (and not the metal-molecule interface) dominates the transport properties. Moreover, our implementation of the WBL requires negligible computational effort compared to the ground state DFT calculation of a molecular junction. We also present a new approximate but efficient scheme for calculating transport with a finite bias. Provided the voltage drop occurs primarily inside the molecule, this method provides results in reasonable agreement with fully self-consistent calculations.

References in corpus (8)

• Dependence of Single Molecule Junction Conductance on Molecular Conformation
• Electron Transport Through Molecules: Self-consistent and Non-self-consistent Approaches
• Renormalization of Molecular Quasiparticle Levels at Metal-Molecule Interfaces: Trends Across Binding Regimes
• Electronic excitations of a single molecule contacted in a three-terminal configuration
• Contact Atomic Structure and Electron Transport Through Molecules
• The Role of the Exchange-Correlation Potential in ab initio Electron Transport Calculations
• A DFT-based Molecular Transport Implementation in ADF/BAND
• Electron transport through single conjugated organic molecules: Basis set effects in ab initio calculations

Cited by in corpus (15)

• Mechanical Tuning of Conductance and Thermopower in Helicene Molecular Junctions
• Comparing the generalized Kadanoff-Baym ansatz with the full Kadanoff-Baym equations for an excitonic insulator out of equilibrium
• A many-body approach to transport in quantum systems: From the transient regime to the stationary state
• Energy-dependent resonance broadening in symmetric and asymmetric molecular junctions from an ab initio non-equilibrium Green's function approach
• Negative differential conductance in molecular junctions: an overview of experiment and theory
• Current-induced forces in nanosystems: A hierarchical equations of motion approach
• Time-resolved impurity-invisibility in graphene nanoribbons
• Charge Transport Through DNA with Energy-Dependent Decoherence
• Stability of destructive interference antiresonances in electron transport through graphene nanostructures
• Efficient simulations with electronic open boundaries
• Electroluminescence rectification and high harmonic generation in molecular junctions
• A Three-Tiered Hierarchical Computational Framework Bridging Molecular Systems and Junction-Level Charge Transport
• Thermoelectric energy conversion in molecular junctions out of equilibrium
• Effect of vacancies on magnetic correlations and conductance in graphene nanoflakes with realistic Coulomb interaction
• Quantum Statistical Mechanics of Electronically Open Molecules: Reduced Density Operators