Experimental Observation of Bethe Strings Institutional Repository Document uri icon

abstract

  • Almost one century ago, string states - complex bound states (Wellenkomplexe) of magnetic excitations - have been predicted to exist in one-dimensional quantum magnets and since then become a subject of intensive theoretical study. However, experimental realization and identification of string states in condensed-matter systems remains an unsolved challenge up to date. Here we use high-resolution terahertz spectroscopy to identify string states in the antiferromagnetic Heisenberg-Ising chain SrCo2V2O8 in strong longitudinal magnetic fields. We observe complex bound states (strings) and fractional magnetic excitations (psinons and antipsinons) in the field-induced critical regime, which are precisely described by the Bethe ansatz. Our study reveals that two-string and three-string states govern the quantum spin dynamics close to the quantum criticality, while the fractional excitations are dominant at low energies, reflecting the antiferromagnetic quantum fluctuations.

author list (cited authors)

  • Wang, Z., Wu, J., Yang, W., Bera, A. K., Kamenskyi, D., Islam, A., ... Loidl, A.

citation count

  • 0

complete list of authors

  • Wang, Zhe||Wu, Jianda||Yang, Wang||Bera, Anup Kumar||Kamenskyi, Dmytro||Islam, ATM Nazmul||Xu, Shenglong||Law, Joseph Matthew||Lake, Bella||Wu, Congjun||Loidl, Alois

Book Title

  • arXiv

publication date

  • June 2017