One-dimensional physics of the frustrated quantum magnet PHCC

2025/12/19 by Tsirlin, Alexander A., Janson, Oleg, Rousochatzakis, Ioannis
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el)

paper · doi:10.48550/arxiv.2512.17406

Abstract

We report a comprehensive microscopic study of the frustrated quantum magnet PHCC, (C₄H₁₂N₂)Cu₂Cl₆, using density-functional band-structure calculations combined with numerical quantum many-body simulations of the underlying spin Hamiltonian. We show that the magnetism of PHCC is captured by a one-dimensional model of the frustrated spin chain with alternating nearest-neighbor couplings (J₁=23.1 K, J₁'=7.0 K) and uniform next-nearest-neighbor couplings (J₂=13.9 K). This model, which can also be thought of as a zigzag ladder, provides a quantitative description of the magnetic susceptibility and the magnetization process, and accounts for the observed dispersion of the single-triplet band and its merging into a continuum near the Brillouin zone center. We also make predictions for the existence of sharp bound (anti-bound) states of two triplets, below (above) the bottom (upper) edge of the two-particle scattering continuum.

Citations

• Phonon spectrum in the spin-Peierls phase of CuGeO₃
• Magnetic excitations in the quantum spin system NH4CuCl3
• Magnetic Excitations of the Spin Gap System TlCuCl₃
• Efficient iterative schemes forab initiototal-energy calculations using a plane-wave basis set
• Crystal Statistics. I. A Two-Dimensional Model with an Order-Disorder Transition

Related

• Frustrated quantum magnets
• Quantum Antiferromagnets in a Magnetic Field
• Crystal structure and magnetic properties of spin-1/2 frustrated two-leg ladder compounds (C₄H₁₄N₂)Cu₂X₆ (X= Cl and Br)
• Microscopic Origin of Reduced Magnetic Order in a Frustrated Metal
• Quantum Magnetism Approaches to Strongly Correlated Electrons