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Entanglement in the Kondo Spin Chain. Abolfazl Bayat 1 , Sougato Bose 1 , Pasquale Sodano 2 1 University College London, London, UK. 2 University of Perugia, Perugia, Italy. Engineering of States and Devices: Theory and Experiments. Contents of the Talk. Quantum Information. Condensed
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Entanglement in the Kondo Spin Chain Abolfazl Bayat1, Sougato Bose1, Pasquale Sodano2 1 University College London, London, UK. 2 University of Perugia, Perugia, Italy. Engineering of States and Devices: Theory and Experiments
Contents of the Talk Quantum Information Condensed Matter 1. Kondo physics 2. Entanglement in the Kondo ground state 3. Generating a long range entanglement
Gapped Systems Excited states Ground state The intrinsic length scale of the system impose an exponential decay
Gapless Systems Continuum of excited states Ground state There is no length scale in the system so correlations decay algebraically
Kondo Physics Despite the gapless nature of the Kondo system, correlations decay exponentially
Kondo Spin Chain E. S. Sorensen et al., J. Stat. Mech., P08003 (2007)
Entanglement as a Witness of the Cloud A B Impurity L
Scaling B A Impurity L N-L-1 Kondo Phase: Dimer Phase:
Scaling Properties of the Kondo regime Kondo Phase: Dimer Phase:
Local Quench Quench
Optimality and Distance independence Independent of length N, when cloud contains N-2 spins we generate a constant Entanglement
Entanglement in the Modified Strategy Kondo: High value distance independent entanglement mediated by the cloud. Dimer: Entanglement is just due to an end-end effect which decays exponentially.
Entanglement Rotor Dispatching centre With interacting the clouds impurities get entangled
Summary of Results • With using the entanglement measures, one can capture the properties of the Kondo physics. • A local quench generates an oscillatory dynamics in the Kondo regime. • Kondo cloud mediates long range distance independent • entanglement between individual ending. • References: • 1- Abolfazl Bayat, Pasquale Sodano, Sougato Bose, Physical Review B 81, 064429 (2010) • 2- Pasquale Sodano, Abolfazl Bayat,Sougato Bose, Physical Review B 81, 100412(R) (2010)