Witnessing entanglement in quantum magnets using neutron scattering

ORAL  · Invited

Abstract

Quantum entanglement is a key driver of exotic physics in quantum materials, but it historically has been extremely hard to measure. I will discuss recent experiments showing how quantum spin entanglement can be extracted from neutron scattering data using the tools of quantum information theory. We applied these protocols to 1D spin chains KCuF3, Cs2CoCl4, and triangular lattice delafossite KYbSe2. Of the three protocols we tested, we found Quantum Fisher Information (QFI) to be the most experimentally robust. Crucially, these protocols do not require theoretical models, which are only sometimes available for 2D and 3D quantum systems. Entanglement witnesses in KYbSe2 show evidence of a proximate quantum spin liquid phase, which is confirmed by comparison to numerical simulations of a 2D triangular lattice spin liquid.

*This research 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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Publication: [1] Scheie, Laruell et al, Phys. Rev. B 103, 224434 (2021)
[2] Laurell, Scheie et al, Phys. Rev. Lett. 127, 037201 (2021)
[3] Scheie et al, ArXiv:2109.11527 (2021)

Presenters

  • Allen O Scheie

    • Oak Ridge National Lab

Authors

  • Allen O Scheie

    • Oak Ridge National Lab

  • Esteban A Ghioldi

    • University of Tennessee

  • Jie Xing

    • Oak Ridge National Lab

  • Joseph Paddison

    • Oak Ridge National Lab

  • Nicholas E Sherman

    • University of California, Berkeley

  • Maxime Dupont

    • University of California, Berkeley

  • Douglas L Abernathy

    • Oak Ridge National Lab

  • Daniel M Pajerowski

    • Oak Ridge National Lab

  • Shang-Shun Zhang

    • University of Minnesota

  • Luis O Manuel

    • Instituto de Física Rosario (CONICET)
    • Instituto de Física Rosario (CONICET) and Universidad Nacional de Rosario, Brd 27 de Febrero 210 bis, (2000) Rosario, Argentina.

  • Adolfo E Trumper

    • Instituto de Física Rosario (CONICET)
    • Instituto de Física Rosario (CONICET) and Universidad Nacional de Rosario, Brd 27 de Febrero 210 bis, (2000) Rosario, Argentina.

  • Das Pemmaraju

    • SLAC National Accelerator Laboratory
    • SLAC Natl Accelerator Lab

  • Athena S Sefat

    • Department of Energy - US

  • David S Parker

    • Oak Ridge National Lab

  • Thomas P Devereaux

    • Stanford Univ
    • Stanford University; SLAC National Accelerator Laboratory
    • Stanford University

  • Joel E Moore

    • University of California, Berkeley

  • Cristian Batista

    • University of Tennessee

  • David A Tennant

    • Oak Ridge National Lab