Spin thermopower in the overscreened Kondo model

Abstract

We study the spin thermopower in the two-channel spin-1/2 Kondo model which exhibits the phenomenon of impurity spin overscreening and non-Fermi-liquid properties. While magnetic field lower than the Kondo temperature does not strongly polarize the impurity spin, we show that it nevertheless strongly affects the low-energy part of the spectral function. In turn, this leads to characteristic saturation of the spin Seebeck coefficient at the value of 0.388kB/|e| at T ~ T*, where T* ~ B^2/TK is the scale of the crossover between the intermediate-temperature non-Fermi-liquid regime and the low-temperature Fermi-liquid regime. We show that measuring the spin thermopower at low magnetic fields would provide a sensitive test for distinguishing regular Fermi liquid, singular Fermi liguid, and non-Fermi liquid behaviour in nanodevices.

15 pages, 5 figures

References in corpus (15)

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• Observation of the two-channel Kondo effect
• Sum-rule Conserving Spectral Functions from the Numerical Renormalization Group
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• Spin-thermopower in interacting quantum dots
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• Theory of inelastic scattering from quantum impurities
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• Dynamical correlations in the spin-half two-channel Kondo model

Cited by in corpus (10)

• Wiedemann-Franz law in a non-Fermi liquid and Majorana central charge: Thermoelectric transport in a two-channel Kondo system
• Thermoelectric response of a correlated impurity in the nonequilibrium Kondo regime
• Fate of the spin-\frac{1}{2} Kondo effect in the presence of temperature gradients
• Spin-dependent thermoelectric effects in transport through a nanoscopic junction involving spin impurity
• Effect of assisted hopping on thermopower in an interacting quantum dot
• Spin-orbital and spin Kondo effects in parallel coupled quantum dots
• Quantum thermodynamics of nanoscale thermoelectrics and electronic devices
• Quantum thermoelectric and heat transport in the overscreened Kondo regime: Exact conformal field theory results
• Interplay of the Kondo effect with the induced pairing in electronic and caloric properties of T-shaped double quantum dots
• Spin filtering and thermopower in star coupled quantum dot devices