Entanglement of an impurity and conduction spins in the Kondo model

Abstract

Based on Yosida's ground state of the single-impurity Kondo Hamiltonian, we study three kinds of entanglement between an impurity and conduction electron spins. First, it is shown that the impurity spin is maximally entangled with all the conduction electrons. Second, a two-spin density matrix of the impurity spin and one conduction electron spin is given by a Werner state. We find that the impurity spin is not entangled with one conduction electron spin even within the Kondo screening length ${\xi }_K$, although there is the spin-spin correlation between them. Third, we show the density matrix of two conduction electron spins is nearly same to that of a free electron gas. The single impurity does not change the entanglement structure of the conduction electrons in contrast to the dramatic change in electrical resistance.

arXiv comment5 pages, 2 figures, accepted for publication in Physical Review B

References in corpus (12)

• Entanglement in quantum critical phenomena
• Scaling of Entanglement close to a Quantum Phase Transitions
• Entanglement in a simple quantum phase transition
• Entanglement versus Correlations in Spin Systems
• Tunable Non-local Spin Control in a Coupled Quantum Dot System
• Scaling theory of the Kondo screening cloud
• Good dynamics versus bad kinematics. Is entanglement needed for quantum computation?
• Entanglement in The Second Quantization Formalism
• Entanglement of electron spins of non-interacting electron gases
• Natural multiparticle entanglement in a Fermi gas
• The Kondo Screening Cloud around a Quantum Dot: Large-scale numerical Results
• Entanglement of electron spins in superconductors

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• Resolving the nonequilibrium Kondo singlet in energy- and position-space using quantum measurements
• Understanding entangled spins in QED
• Entanglement in Anderson Nanoclusters
• Electron-electron correlations in a dynamical impurity system with a Fermi edge singularity
• Diatomic molecule as a quantum entanglement switch
• Linear response of a one-dimensional conductor coupled to a dynamical impurity with a Fermi edge singularity
• Quantum Separability of Thermal Spin One Boson Systems