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Showing 1 to 20 of 90 for “"Kondo"”.
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Kondo effect out of equilibrium
… for the model system of a quantum dot in the Kondo regime using the real time renormalization group (RTRG) method. This method is a functional renormalization group (RG) method allowing a non-perturbative description of correlated systems in non-equilibrium. For the Kondo quantum dot the …
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Flußgleichungen für das Kondo-Modell
In der vorliegenden Arbeit werden das Ein-Kanal-Kondo-Modell (1CK) und das Zwei-Kanal-Kondo-Modell (2CK) untersucht. Das 1CK beschreibt ein System aus Leitungselektronen und einer lokalisierten, spinbehafteten Störstelle, die untereinander antiferromagnetisch wechselwirken. Das 2CK erweitert dieses …
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Nuclear Magnetic Resonance on the Kondo Effect
Submitted by Jesse Garrison (jagarris@illinois.edu) on 2011-11-08T19:15:36Z No. of bitstreams: 1 1972_lo.pdf: 3080925 bytes, checksum: 84d96cc7ebfc5bf61970aa7f08cd9b18 (MD5)
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Nuclear Magnetic Resonance (Nmr) on the Kondo Effect
Made available in DSpace on 2015-05-12T22:38:51Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 7309986.PDF: 2916569 bytes, checksum: 967ea9fcf2d4088b876eefe59106c062 (MD5) Previous issue date: 1972
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The Kondo effect in a single-electron transistor
The Kondo effect, which occurs when a metal with magnetic impurities is cooled to low temperatures, has been a focus of research in solid-state physics for several decades. I have designed, fabricated, and measured a system which behaves as a single "artificial" impurity in a metal, displaying the …
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Magnetic-field-induced antiferromagnetism in the Kondo lattice
The half-filled Kondo lattice model, augmented by a Zeeman term, serves as a useful model of a Kondo insulator in an applied magnetic field. A variational mean field analysis of this system on a square lattice, backed up by quantum Monte Carlo calculations, reveals an interesting separation of …
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Noise in coulomb blockaded quantum dots and kondo systems
In this thesis we study the noise in Coulomb blockaded quantum dots in the vicinity of the peak of conductance in a full quantum treatment using the Keldysh technique. In previous work on this system, the emphasis have been on master equation approaches in the shot noise regime. In the vicinity of …
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Path integral methods for the large-N Kondo model
A path integral formulation of the SU(N) Kondo model is explored as a possible theoretical tool for studying generalizations of the model, such as the Kondo lattice, which are difficult to study by other means. Saddle point approximations to the path integral lead to an expansion in powers of 1/N. …
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Competition and unification of Kondo coherence and magnetic ordering
… this simultaneous collapse, we study the Kondo-Heisenberg model on the honeycomb lattice at half-filling. We study a fixed point controlling the quantum phase transition of a Kondo coherent phase to a critical phase called algebraic spin liquid. Studying such a fixed point has been …
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The diagramatical solution of the two-impurity Kondo problem
The problem of the two-impurity Kondo problem is studied via the perturbative diagrammatical method. The high-temperature magnetic susceptibility is calculated to fourth order in the coupling constant J for different regimes. The integral equations for the ground state energy are established and …
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Flussgleichungen zur Beschreibung statischer und dynamischer Eigenschaften des eindimensionalen Kondo-Gitter-Modells
In dieser Arbeit wird das eindimensionale Kondo-Gitter-Modell untersucht, das die Wechselwirkung eines Gitters lokaler magnetischer Momente mit unkorrelierten Leitungselektronen beschreibt. Mit Hilfe der Methode der kontinuierlichen unitären Transformationen (Flussgleichungen) wird das Modell im …
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Theoretical study of Kondo effect and related transport properties in topological insulator systems
This thesis presents theoretical studies of the Kondo effect and related transport properties in topological insulator systems. The thesis mainly covers two topics: the Kondo effect on the surface of a bulk topological insulator material and the Kondo effect in a topological insulator quantum dot. …
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Phase diagram for the S equals one-half and J equals three-halves Kondo lattice model
A Kondo lattice Hamiltonian for arbitrary total angular momentum J is formulated using a pseudofermion representation and without addition of RKKY interaction terms. An Hartree-Fock treatment is applied, and both variational and Green's function methods are used to calculate physical quantities …
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Fermi Surfaces and Where to Find Them: Quantum Oscillations in Kondo Insulators and High-Temperature Superconductors
… of SmB₆ and YbB₁₂, two strongly-correlated Kondo insulators. We also present magnetic and transport measurements of underdoped YBa₂Cu₃O₆₊ₓ, a high-temperature superconductor, that prompt us to reinterpret the quantum oscillations previously associated with the non-superconducting normal …
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Electrical resistivity of the kondo systems (Ce1−xREx)In3, RE = Gd, Tb, Dy AND Ce(Pt1−xNix)Si2
… of the hybridization by substituting Ce atom in Kondo lattice CeIn3 with Gd, Tb, and Dy and by changing the chemical environment around the Ce atom in substituting Pt with Ni in CePtSi2. This thesis covers four chapters outline as follows: Chapter 1 introduces the theoretical background in rare …
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Magnetoconductance and Dynamic Phenomena in Single-Electron Transistors
… characteristic temperature. This is known as the Kondo effect and the characteristic temperature is called the Kondo temperature. This temperature is expected to be the only energy scale that is involved in a Kondo system. This report investigates the universality of the Kondo energy scale. …
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Spin effects in single-electron transistors
… inelastic cotunneling thresholds, the spin-1/2 Kondo effect, and Fano interference. With a magnetic field parallel to the motion of the electrons, single-particle energy levels undergo Zeeman splitting according to their spin. The g-factor describing this splitting is extracted in the spin-flip …
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