Transport properties and Kondo correlations in nanostructures: Time-dependent DMRG method applied to quantum dots coupled to Wilson chains

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.78.195317· OSTI ID:979252

Dias Da Silva, Luis G ^[1]; Heidrich-Meisner, Fabian ^[1]; Feiguin, Adrian E ^[1]; Busser, C. A. ^[2]; Martins, G. B. ^[2]; Anda, E. V. ^[3]; Dagotto, Elbio R ^[1]

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1. ORNL
2. Oakland University, Rochester, MI
3. Pontificia Universidade, Brazil

We apply the adaptive time-dependent density-matrix renormalization-group method tDMRG to the study of transport properties of quantum-dot systems connected to metallic leads. Finite-size effects make the usual tDMRG description of the Kondo regime a numerically demanding task. We show that such effects can be attenuated by describing the leads by Wilson chains, in which the hopping matrix elements decay exponentially away from the impurity tn n/2. For a given system size and in the linear-response regime, results for 1 show several improvements over the undamped =1 case: perfect conductance is obtained deeper in the strongly interacting regime and current plateaus remain well defined for longer time scales. Similar improvements were obtained in the finite-bias regime up to bias voltages of the order of the Kondo temperature. These results show that with the proposed modification, the tDMRG characterization of Kondo correlations in the transport properties can be substantially improved, while it turns out to be sufficient to work with much smaller system sizes. We discuss the numerical cost of this approach with respect to the necessary system sizes and the entanglement growth during the time evolution.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 979252
• Journal Information: Physical Review B, Journal Name: Physical Review B Journal Issue: 19 Vol. 78; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHAINS
DECAY
DENSITY MATRIX
MATRIX ELEMENTS
NANOSTRUCTURES
QUANTUM DOTS
TRANSPORT