Universal Crossover in the Three-Channel Charge Kondo Model at High Transparency

Fuente: arXiv
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Main Authors: Paris, Nicolas, Dupuis, Nicolas, Mora, Christophe
Format: Preprint
Published: 2025
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_version_ 1866915795242582016
author Paris, Nicolas
Dupuis, Nicolas
Mora, Christophe
author_facet Paris, Nicolas
Dupuis, Nicolas
Mora, Christophe
contents Quantum impurity models provide a central framework for correlated electron physics, with quantum dots enabling controlled experimental realizations. While their weak-coupling behavior is well understood through mappings to Kondo Hamiltonians, the opposite regime of highly transparent contacts has lacked a controlled theoretical description. Using the functional renormalization group (FRG), we resolve this regime for the three-channel charge Kondo device of Ref.~\cite{iftikhar2018}, benchmarking against conformal field theory by reproducing the universal zero-frequency conductance and, crucially, going beyond it to obtain the full frequency crossover of the conductance and the full temperature crossover of the impurity entropy, together with a continuous line of fixed points for interacting leads. These results establish FRG as a powerful nonperturbative tool for quantum impurity problems in regimes inaccessible to conventional approaches, with direct implications for mesoscopic experiments.
format Preprint
id arxiv_https___arxiv_org_abs_2509_03612
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Universal Crossover in the Three-Channel Charge Kondo Model at High Transparency
Paris, Nicolas
Dupuis, Nicolas
Mora, Christophe
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
Quantum Physics
Quantum impurity models provide a central framework for correlated electron physics, with quantum dots enabling controlled experimental realizations. While their weak-coupling behavior is well understood through mappings to Kondo Hamiltonians, the opposite regime of highly transparent contacts has lacked a controlled theoretical description. Using the functional renormalization group (FRG), we resolve this regime for the three-channel charge Kondo device of Ref.~\cite{iftikhar2018}, benchmarking against conformal field theory by reproducing the universal zero-frequency conductance and, crucially, going beyond it to obtain the full frequency crossover of the conductance and the full temperature crossover of the impurity entropy, together with a continuous line of fixed points for interacting leads. These results establish FRG as a powerful nonperturbative tool for quantum impurity problems in regimes inaccessible to conventional approaches, with direct implications for mesoscopic experiments.
title Universal Crossover in the Three-Channel Charge Kondo Model at High Transparency
topic Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
Quantum Physics
url https://arxiv.org/abs/2509.03612