2003/03/18 by M. B. Stone, D. H. Reich, Daniel H. Reich +9 · 138 citations
Materials Science · Physics and Astronomy · #Antiferromagnetism #Bethe ansatz #Condensed matter physics #Magnetism in coordination complexes #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum and electron transport phenomena #Quantum mechanics #Spin (aerodynamics) #Spinon #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.91.037205
published in Physical Review Letters 91(3), 037205 (American Physical Society) · 4 pages, 4 figures
arxiv created 2003/03/18 · openalex publication_date 2003/07/17 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Measurements are reported of the magnetic field dependence of excitations in the quantum critical state of the spin S=1/2 linear chain Heisenberg antiferromagnet copper pyrazine dinitrate (CuPzN). The complete spectrum was measured at k(B)T/J< or =0.025 for H=0 and H=8.7 T, where the system is approximately 30% magnetized. At H=0, the results are in agreement with exact calculations of the dynamic spin correlation function for a two-spinon continuum. At H=8.7 T, there are multiple overlapping continua with incommensurate soft modes. The boundaries of these continua confirm long-standing predictions, and the intensities are consistent with exact diagonalization and Bethe ansatz calculations.