Role of bias and tunneling asymmetries in nonlinear Fermi-liquid transport through an SU($N$) quantum dot
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arXiv
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| Autores principales: | , , , , |
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| Formato: | Preprint |
| Publicado: |
2023
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| _version_ | 1866913883352989696 |
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| author | Tsutsumi, Kazuhiko Teratani, Yoshimichi Motoyama, Kaiji Sakano, Rui Oguri, Akira |
| author_facet | Tsutsumi, Kazuhiko Teratani, Yoshimichi Motoyama, Kaiji Sakano, Rui Oguri, Akira |
| contents | We study how bias and tunneling asymmetries affect nonlinear current through a quantum dot with $N$ discrete levels in the Fermi liquid regime, using an exact low-energy expansion of the current derived up to terms of order $V^3$ with respect to the bias voltage. The expansion coefficients are described in terms of the phase shift, the linear susceptibilities, and the three-body correlation functions, defined with respect to the equilibrium ground state of the Anderson impurity model. In particular, the three-body correlations play an essential role in the order $V^3$ term, and their coupling to the nonlinear current depends crucially on the bias and tunnel asymmetries. The number of independent components of the three-body correlation functions increases with $N$ the internal degrees of the quantum dots, and it gives a variety in the low-energy transport. We calculate the correlation functions over a wide range of electron fillings of the Anderson impurity model with the SU($N$) internal symmetry, using the numerical renormalization group. We find that the order $V^3$ nonlinear current through the SU($N$) Kondo state, which occurs at electron fillings of $1$ and $N-1$ for strong Coulomb interactions, significantly varies with the three-body contributions as tunnel asymmetries increase. Furthermore, in the valence fluctuation regime toward the empty or fully occupied impurity state, a sharp peak emerges in the coefficient of $V^3$ current in the case at which bias and tunneling asymmetries cooperatively enhance the charge transfer from one of the electrodes. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2305_01162 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Role of bias and tunneling asymmetries in nonlinear Fermi-liquid transport through an SU($N$) quantum dot Tsutsumi, Kazuhiko Teratani, Yoshimichi Motoyama, Kaiji Sakano, Rui Oguri, Akira Mesoscale and Nanoscale Physics Strongly Correlated Electrons We study how bias and tunneling asymmetries affect nonlinear current through a quantum dot with $N$ discrete levels in the Fermi liquid regime, using an exact low-energy expansion of the current derived up to terms of order $V^3$ with respect to the bias voltage. The expansion coefficients are described in terms of the phase shift, the linear susceptibilities, and the three-body correlation functions, defined with respect to the equilibrium ground state of the Anderson impurity model. In particular, the three-body correlations play an essential role in the order $V^3$ term, and their coupling to the nonlinear current depends crucially on the bias and tunnel asymmetries. The number of independent components of the three-body correlation functions increases with $N$ the internal degrees of the quantum dots, and it gives a variety in the low-energy transport. We calculate the correlation functions over a wide range of electron fillings of the Anderson impurity model with the SU($N$) internal symmetry, using the numerical renormalization group. We find that the order $V^3$ nonlinear current through the SU($N$) Kondo state, which occurs at electron fillings of $1$ and $N-1$ for strong Coulomb interactions, significantly varies with the three-body contributions as tunnel asymmetries increase. Furthermore, in the valence fluctuation regime toward the empty or fully occupied impurity state, a sharp peak emerges in the coefficient of $V^3$ current in the case at which bias and tunneling asymmetries cooperatively enhance the charge transfer from one of the electrodes. |
| title | Role of bias and tunneling asymmetries in nonlinear Fermi-liquid transport through an SU($N$) quantum dot |
| topic | Mesoscale and Nanoscale Physics Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2305.01162 |