Measuring Quantum Entanglement in Spin Chain KCuF<sub>3</sub> using Neutron Scattering

ORAL

Abstract

We use neutron scattering to directly witness entanglement between quantum spins in the 1D Heisenberg antiferromagnet KCuF3. We apply three entanglement witnesses---one-tangle, two-tangle, and quantum fisher information---to its inelastic neutron spectrum, and compare with simulated DMRG spectra. We find that each of these provides direct access to entanglement, but quantum fisher information is the most robust experimentally. This 1D system serves as a proof-of-principle that solid state quantum spin entanglement can be directly measured. We outline how these results can be applied to higher dimensional and higher spin materials to witness and quantify entanglement in quantum materials.

*The research was supported by the Scientific Discovery through Advanced Computing (SciDAC) program funded by the US Department of Energy, Office of Science, Advanced Scientific Computing Research and Basic Energy Sciences, Division of Materials Sciences and Engineering. This research also used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory.

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Presenters

  • Allen Scheie

    • Oak Ridge National Lab

Authors

  • Allen Scheie

    • Oak Ridge National Lab

  • Pontus Laurell

    • Oak Ridge National Lab

  • Anjana Samarakoon

    • Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN
    • Oak Ridge National Lab

  • Bella A C I Lake

    • Technische Universitat Berlin, Institut fur Festkorperphysik
    • Helmholtz-Zentrum Berlin

  • Stephen E Nagler

    • Oak Ridge National Lab
    • Oak Ridge National Laboratory
    • Oakridge National Laboratory
    • Neutron Scattering Division, Oak Ridge National Laboratory

  • Satoshi Okamoto

    • Oak Ridge National Lab
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory

  • Gonzalo Alvarez

    • Oak Ridge National Lab
    • Oak Ridge National Laboratory
    • Computational Sciences and Engineering Division, Oak Ridge National Laboratory
    • Center for Nanophase Materials Sciences, Oak Ridge National Laboratory
    • Computational Sciences & Engineering Division and Center for Nanophase Materials Sciences, Oak Ridge National Laboratory
    • Computational Sciences and Engineering Division and Center for Nanophase Materials Sciences, Oak Ridge National Laboratory

  • David A Tennant

    • Oak Ridge National Lab
    • Oak Ridge National Laboratory