Numerical renormalization group approach to a quartet quantum-dot array connected to reservoirs:gate-voltage dependence of the conductance
| dc.creator | Nisikawa, Yunori | |
| dc.creator | Oguri, Akira | |
| dc.date | 2005-11-08 | |
| dc.date | 2006-01-16 | |
| dc.date.accessioned | 2026-07-07T06:45:55Z | |
| dc.date.available | 2026-07-07T06:45:55Z | |
| dc.description | The ground-state properties of quartet quantum-dot arrays are studied using the numerical renormalization group (NRG) method with a four-site Hubbard model connected to two non-interacting leads. Specifically, we calculate the conductance and local charge in the dots from the many-body phase shifts, which can be deduced from the fixed-point eigenvalues of NRG. As a function of the on-site energy $ε_d$ which corresponds to the gate voltage, the conductance shows alternatively wide peak and valley. Simultaneously, the total number of electrons $N_{\rm el}$ in the four dots shows a quantized stair case behavior due to a large Coulomb interaction $U$. The conductance plateaus of the Unitary limit emerging for odd $N_{\rm el}$ are caused by the Kondo effect. The valleys of the conductance emerge for even $N_{\rm el}$, and their width becomes substantially large at half-filling. It can be regarded as a kind of the Mott-Hubbard insulating behavior manifesting in a small system. These structures of the plateaus and valleys become weak for large values of the hybridization strength $Γ$ between the chain and leads. We also discuss the parallel conductance for the array connected to four leads. | |
| dc.description | 8 pages, 9 figures | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0511182 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0511182 | |
| dc.identifier | Phy. Rev. B 73, 125108 (2006) | |
| dc.identifier | doi:10.1103/PhysRevB.73.125108 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/103181 | |
| dc.subject | Strongly Correlated Electrons | |
| dc.title | Numerical renormalization group approach to a quartet quantum-dot array connected to reservoirs:gate-voltage dependence of the conductance | |
| dc.type | text |