Thermoelectric transport and current noise through a multilevel Anderson impurity: Three-body Fermi-liquid corrections in quantum dots and magnetic alloys
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| Autores principales: | , , , , |
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| Formato: | Preprint |
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2024
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| _version_ | 1866913574809501696 |
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| author | Teratani, Yoshimichi Tsutsumi, Kazuhiko Motoyama, Kaiji Sakano, Rui Oguri, Akira |
| author_facet | Teratani, Yoshimichi Tsutsumi, Kazuhiko Motoyama, Kaiji Sakano, Rui Oguri, Akira |
| contents | We present a comprehensive Fermi-liquid description for thermoelectric transport and current noise, applicable to multilevel quantum dots (QD) and magnetic alloys (MA) without electron-hole or time-reversal symmetry. Our formulation for the low-energy transport is based on an Anderson model with $N$ discrete impurity levels, and is asymptotically exact at low energies, up to the next-leading order terms in power expansions with respect to temperature $T$ and bias voltage $eV$. The expansion coefficients can be expressed in terms of the Fermi-liquid parameters, which include the three-body correlation functions defined with respect to the equilibrium ground state in addition to the linear susceptibilities and the occupation number $N_d^{}$ of impurity electrons. We apply this formulation to SU($N$) symmetric QD and MA, and calculate the correlation functions for $N=4$ and $6$, using the numerical renormalization group approach. The three-body correlations are shown to be determined by a single parameter over a wide range of electron fillings $1 \lesssim N_d^{} \lesssim N-1$ for strong Coulomb interactions $U$, and they also exhibit the plateau structures due to the SU($N$) Kondo effects at integer values of $N_d^{}$. We find that the Lorenz number $L=κ/(T σ)$ for QD and MA, defined as the ratio of the thermal conductivity $κ$ to the electrical conductivity $σ$, deviates from the universal Wiedemann-Franz value $π^2/(3e^2)$ as the temperature increases from $T=0$, showing the $T^2$ dependence, the coefficient for which depends on the three-body correlations away from half filling. We also demonstrate the role of three-body correlations on the nonlinear current noise and the other transport coefficients. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2404_05947 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Thermoelectric transport and current noise through a multilevel Anderson impurity: Three-body Fermi-liquid corrections in quantum dots and magnetic alloys Teratani, Yoshimichi Tsutsumi, Kazuhiko Motoyama, Kaiji Sakano, Rui Oguri, Akira Mesoscale and Nanoscale Physics Strongly Correlated Electrons We present a comprehensive Fermi-liquid description for thermoelectric transport and current noise, applicable to multilevel quantum dots (QD) and magnetic alloys (MA) without electron-hole or time-reversal symmetry. Our formulation for the low-energy transport is based on an Anderson model with $N$ discrete impurity levels, and is asymptotically exact at low energies, up to the next-leading order terms in power expansions with respect to temperature $T$ and bias voltage $eV$. The expansion coefficients can be expressed in terms of the Fermi-liquid parameters, which include the three-body correlation functions defined with respect to the equilibrium ground state in addition to the linear susceptibilities and the occupation number $N_d^{}$ of impurity electrons. We apply this formulation to SU($N$) symmetric QD and MA, and calculate the correlation functions for $N=4$ and $6$, using the numerical renormalization group approach. The three-body correlations are shown to be determined by a single parameter over a wide range of electron fillings $1 \lesssim N_d^{} \lesssim N-1$ for strong Coulomb interactions $U$, and they also exhibit the plateau structures due to the SU($N$) Kondo effects at integer values of $N_d^{}$. We find that the Lorenz number $L=κ/(T σ)$ for QD and MA, defined as the ratio of the thermal conductivity $κ$ to the electrical conductivity $σ$, deviates from the universal Wiedemann-Franz value $π^2/(3e^2)$ as the temperature increases from $T=0$, showing the $T^2$ dependence, the coefficient for which depends on the three-body correlations away from half filling. We also demonstrate the role of three-body correlations on the nonlinear current noise and the other transport coefficients. |
| title | Thermoelectric transport and current noise through a multilevel Anderson impurity: Three-body Fermi-liquid corrections in quantum dots and magnetic alloys |
| topic | Mesoscale and Nanoscale Physics Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2404.05947 |