Speaker: 寺谷義道（大阪市大）

Date: May 24th 17:00-

Title: Effects of three-body correlations on nonlinear current and noise through a multilevel Anderson impurity

Abstract

We study nonlinear transport phenomena in -level Anderson impurity models with a microscopic Fermi-liquid theory which is applicable to arbitrary electron filling [1-3]. We examine the nonlinear current and noise at low-bias voltages eV. The theory shows that the current and noise up to order of (eV)^3 are determined by Fermi-liquid parameters: phase shifts, two-body correlations, and three-body correlations. We calculate these parameters as functions of N_d for N=4,6, and 8 using two methods: Wilson numerical renormalization group(NRG)[4] and 1/(N-1) expansion[5]. The latter one is a large N theory which is exact in the limit of N-> infty. The NRG results show that the three-body correlations significantly contribute to the current and noise as N_d deviates from half-filling. We find that the correlations can be described by a single parameter in a range of 1< N_d < N for strong interactions. Such behavior of the correlations is experimentally observed[6]. Furthermore, we compare the NRG results with results obtained by 1/(N-1) expansion and find that the three-body correlations are suppressed already for N=8.

[1] A. Oguri and A. C. Hewson, Phys. Rev. B 97, 035435 (2018).

[2] M. Filippone, et al, Phys. Rev. B 98, 075404 (2018).

[3] Y. Teratani, R. Sakano, and A. Oguri, Phys. Rev. Lett. 125, 216801 (2020).

[4] H. R. Krishna-murthy, et al, Phys. Rev. B 21, 1003 (1980).

[5] A. Oguri, Phys. Rev. B 85, 155404 (2012).

[6] T. Hata, Y. Teratani, T. Arakawa, S. Lee, M. Ferrier, R. Deblock, R. Sakano,

A. Oguri, and K. Kobayashi, DOI: 10.21203/rs.3.rs-91730/v1.