Witnessing Entanglement and Quantum Correlations in Condensed Matter

ORAL  · Invited

Abstract

The identification of e.g. quantum spin liquid materials is a challenging task, yet it is vital for the development of magnetic based quantum information technologies. A principal problem is the lack of single, unambiguous measurements that can uniquely identify the quantum states involved without the costly and technically difficult step of creating quantum interferometers with the materials in question. To address this urgent need we have developed a protocol that uses innovations in quantum measurement theory, Hamiltonian determination with neutrons, and validation against theoretical predictions to down-select materials. This involves demonstrating the extraction of quantum entanglement witnesses from neutron scattering data that quantify the degree of entanglement of the spins in the material with the rest of the spins in the network as well as the entanglement depth of this network. Our results, and the application of the protocol, are illustrated on triangular quantum spin liquid candidates. A range of quantum materials and application of quantum measures are given and future prospects discussed.

*The work by D.A.T. is supported by the Quantum Science Center (QSC), a National Quantum Information Science Research Center of the U.S. Department of Energy (DOE).

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Publication: 1. Tutorial: Extracting entanglement signatures from neutron spectroscopy, Allen Scheie, Pontus Laurell, Elbio Dagotto, D. Alan Tennant, https://doi.org/10.48550/2409.15249 (2024).
2. Spectrum and low-energy gap in triangular quantum spin liquid NaYbSe2, A. O. Scheie, Minseong Lee, Kevin Wang, P. Laurell, E. S. Choi, D. Pajerowski, Qingming Zhang, Jie Ma, H. D. Zhou, Sangyun Lee, S. M. Thomas, M. O. Ajeesh, P. F. S. Rosa, Ao Chen, Vivien S. Zapf, M. Heyl, C. D. Batista, E. Dagotto, J. E. Moore, D. A. Tennant, https://doi.org/10.48550/arXiv.2406.17773
3. Witnessing Entanglement and Quantum Correlations in Condensed Matter: A Review, Pontus Laurell, Allen Scheie, Elbio Dagotto, D. Alan Tennant, Advanced Quatnum Technologies, in press (2024); https://doi.org/10.48550/arXiv.2405.10899
4. Magnetic field-temperature phase diagram of spin-1/2 triangular lattice antiferromagnet KYbSe2, Sangyun Lee, Andrew J. Woods, Minseong Lee, Shengzhi Zhang, Eun Sang Choi, A. O. Scheie, D. A. Tennant, J. Xing, A. S. Sefat, R. Movshovich, Phys. Rev. B 109 155129 (2024); https://doi.org/10.1103/PhysRevB.109.155129 .
5. Reconstructing the spatial structure of quantum correlations, A. Scheie, P. Laurell, E. Dagotto, D.A. Tennant, T. Roscilde, Physical Review Research 21 June (2024); ArXiv:2306.11723.
6. A. O. Scheie, E. A. Ghioldi, J. Xing, J. A. M. Paddison, N. E. Sherman, M. Dupont, D.Abernathy, D. M. Pajerowski, Shang-Shun Zhang, L. O. Manuel, A. E. Trumper, C. D. Pemmaraju, A.S. Sefat, D. S. Parker, T. P. Devereaux, J. E. Moore, C. D. Batista, and D. A. Tennant, "Proximate spin liquids and fractionalization in the triangular antiferromagnet KYbSe2", Nature Physics 20 74 (2024); https://doi.org/10.1038/s41567-023-02259-1.

Presenters

  • David Alan Tennant

    • University of Tennessee

Authors

  • David Alan Tennant

    • University of Tennessee

  • Allen O Scheie

    • Los Alamos National Laboratory (LANL)

  • Pontus Laurell

    • University of Missouri