Effects of disorder on conductance through small interacting systems.pdfVIP

2 0 0 2 p e S 0 Effects of disorder on conductance through small interacting systems 2 Yoshihide Tanaka 1 and Akira Oguri ] a l Department of Material Science, Faculty of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan l a h - s e Abstract m We study the effects of disorders on the transport through small interacting systems based on a two-dimensional t. Hubbard cluster of finite size connected to two noninteracting leads. This system can be regarded as a model for the a superlattice of quantum dots or atomic network of the nanometer size. We calculate the conductance at T = 0 using m the order U2 self-energy in an electron-hole symmetric case. The results show that the conductance is sensitive to - the randomness when the resonance states are situated near the Fermi energy. d n o Key words: quantum transport; mesoscopic system; electron correlation; disorder; Hubbard model; two dimension c [ 1 Quantum transport through small interacting sys- channels described by Hmix [1]. We assume that the v tems, such as quantum dots and wires, has been a sub- two coupling are equal and described by a parameter 5 2 8 ject of current interest. For these systems theoretical Γ = πρ v , where v is the mixing matrix element and 4 approaches, which are able to treat correctly the inter- ρ is the density of states of the isolated leads. The sys- 9 action and interference effects, are necessary for sys- tem may be regarded as a model for the superlattice of 0 tematic investigations. In this report, using the pertur- quantum dots [2]. 2 bation method described in [1], we study effects