Two-channel charge-Kondo physics in graphene quantum dots
arXiv:2204.02226 · doi:10.3390/nano12091513
Abstract
Nanoelectronic quantum dot devices exploiting the charge-Kondo paradigm have been established as versatile and accurate analog quantum simulators of fundamental quantum impurity models. In particular, hybrid metal-semiconductor dots connected to two metallic leads realize the two-channel Kondo (2CK) model, in which Kondo screening of the dot charge pseudospin is frustrated. Here, we consider theoretically a two-channel charge-Kondo device made instead from graphene components, realizing a pseudogapped version of the 2CK model. We solve the model using Wilson's Numerical Renormalization Group method, and uncover a rich phase diagram as a function of dot-lead coupling strength, channel asymmetry, and potential scattering. The complex physics of this system is explored through its thermodynamic properties, scattering T-matrix, and experimentally measurable conductance. We find that the strong coupling pseudogap Kondo phase persists in the channel-asymmetric two-channel context, while in the channel-symmetric case frustration results in a novel quantum phase transition. Remarkably, despite the vanishing density of states in the graphene leads at low energies, we find a finite linear conductance at zero temperature at the frustrated critical point, which is of non-Fermi liquid type. Our results suggest that the graphene charge-Kondo platform offers a unique possibility to access multichannel pseudogap Kondo physics.
arXiv comment12 pages, 4 figures
References in corpus (45)
- The electronic properties of graphene
- Kondo Physics in a Single Electron Transistor
- A Tunable Kondo Effect in Quantum Dots
- The numerical renormalization group method for quantum impurity systems
- The Kondo Effect in the Unitary Limit
- Real-time dynamics in Quantum Impurity Systems: A Time-dependent Numerical Renormalization Group Approach
- Tunable Kondo Effect in Graphene with Defects
- Observation of the two-channel Kondo effect
- Sum-rule Conserving Spectral Functions from the Numerical Renormalization Group
- Kondo effect in quantum dots coupled to ferromagnetic leads
- Coulomb blockade at almost perfect transmission
- A Numerical Renormalization Group approach to Green's Functions for Quantum Impurity Models
- Kondo effect in quantum dots
- Renormalization-group study of Anderson and Kondo impurities in gapless Fermi systems
- Two-channel Kondo effect and renormalization flow with macroscopic quantum charge states
- Quantum-Coherent Nanoscience
- Impurity Quantum Phase Transitions
- Anderson impurity in pseudo-gap Fermi systems
- Phase transitions in the pseudogap Anderson and Kondo models: Critical dimensions, renormalization group, and local-moment criticality
- The Physics of Kondo Impurities in Graphene
- Observation of the SU(4) Kondo state in a double quantum dot
- Theory of strong inelastic co-tunneling
- Tunable Quantum Criticality and Super-ballistic Transport in a `Charge' Kondo Circuit
- Universal Fermi liquid crossover and quantum criticality in a mesoscopic device
- Upper-critical dimension in a quantum impurity model: Critical theory of the asymmetric pseudogap Kondo problem
- Kondo effect in three-dimensional Dirac and Weyl systems
- Many Body Effects on Electron Tunneling through Quantum Dots in an Aharonov-Bohm Circuit
- Gate-controlled Kondo screening in graphene: Quantum criticality and electron-hole asymmetry
- Quantum phase transition in quantum dot trimers
- Kondo effect of impurity moments in d-wave superconductors: Quantum phase transition and spectral properties
- Real-space renormalization group flow in quantum impurity systems: local moment formation and the Kondo screening cloud
- Fractional entropy of multichannel Kondo systems from conductance-charge relations
- Two-channel Kondo physics in two-impurity Kondo models
- Universal low-temperature crossover in two-channel Kondo models
- A Local Moment Approach to magnetic impurities in gapless Fermi systems
- Kondo effect on the surface of 3D topological insulators: Signatures in scanning tunneling spectroscopy
- Universality and scaling in a charge two-channel Kondo device
- Entropy measurement of a strongly coupled quantum dot
- The Coulomb Blockade in Quantum Boxes
- Quantum phase transitions and thermodynamics of the power-law Kondo model
- SO(5) non-Fermi liquid in a Coulomb box device
- Detecting Kondo Entanglement by Electron Conductance
- Two-channel pseudogap Kondo and Anderson models: Quantum phase transitions and non-Fermi liquids
- Poor man's scaling: anisotropic Kondo and Coqblin--Schrieffer models
- Linear response quantum transport through interacting multi-orbital nanostructures