Transport through quantum dots: A combined DMRG and cluster-embedding study
arXiv:0705.1801 · doi:10.1140/epjb/e2009-00036-4
Abstract
The numerical analysis of strongly interacting nanostructures requires powerful techniques. Recently developed methods, such as the time-dependent density matrix renormalization group (tDMRG) approach or the embedded-cluster approximation (ECA), rely on the numerical solution of clusters of finite size. For the interpretation of numerical results, it is therefore crucial to understand finite-size effects in detail. In this work, we present a careful finite-size analysis for the examples of one quantum dot, as well as three serially connected quantum dots. Depending on odd-even effects, physically quite different results may emerge from clusters that do not differ much in their size. We provide a solution to a recent controversy over results obtained with ECA for three quantum dots. In particular, using the optimum clusters discussed in this paper, the parameter range in which ECA can reliably be applied is increased, as we show for the case of three quantum dots. As a practical procedure, we propose that a comparison of results for static quantities against those of quasi-exact methods, such as the ground-state density matrix renormalization group (DMRG) method or exact diagonalization, serves to identify the optimum cluster type. In the examples studied here, we find that to observe signatures of the Kondo effect in finite systems, the best clusters involving dots and leads must have a total z-component of the spin equal to zero.
16 pages, 14 figures, revised version to appear in Eur. Phys. J. B, additional references
References in corpus (23)
- The numerical renormalization group method for quantum impurity systems
- Real time evolution using the density matrix renormalization group
- The ALPS project release 1.3: open source software for strongly correlated systems
- Real-time dynamics in Quantum Impurity Systems: A Time-dependent Numerical Renormalization Group Approach
- New Trends in Density Matrix Renormalization
- Iterative real-time path integral approach to nonequilibrium quantum transport
- Twofold advance in the theoretical understanding of far-from-equilibrium properties of interacting nanostructures
- Strongly correlated regimes in a double quantum-dot device
- Kondo screening cloud in a one dimensional wire: Numerical renormalization group study
- A novel approach to transport through correlated quantum dots
- Transport properties and Kondo correlations in nanostructures: the time-dependent DMRG method applied to quantum dots coupled to Wilson chains
- Spin Correlations and Finite-Size Effects in the One-dimensional Kondo Box
- Exact ground state density functional theory for impurity models coupled to external reservoirs and transport calculations
- Strong enhancement of transport by interaction on contact links
- Time-dependent DMRG Study on Quantum Dot under a Finite Bias Voltage
- Fermi-liquid versus non-Fermi-liquid behavior in triple quantum dots
- Magnetoconductance through a vibrating molecule in the Kondo regime
- Conductance through an array of quantum dots
- A Novel Approach to Study Highly Correlated Nanostructures: The Logarithmic Discretization Embedded Cluster Approximation
- Kondo effect in transport through molecules adsorbed on metal surfaces: from Fano dips to Kondo peaks
- Non-equilibrium transport through a point contact in the non-Abelian quantum Hall state
- Anderson impurity in the one-dimensional Hubbard model on finite size systems
- Two-channel Kondo tunneling in triple quantum dot