Nuclear magnetic resonance study of the magnetic-field-induced ordered phase in theNiCl2−4SC(NH2)2compound
Skip to main content
eScholarship
Open Access Publications from the University of California

Nuclear magnetic resonance study of the magnetic-field-induced ordered phase in theNiCl2−4SC(NH2)2compound

  • Author(s): Blinder, Rémi
  • Dupont, Maxime
  • Mukhopadhyay, Sutirtha
  • Grbić, Mihael S
  • Laflorencie, Nicolas
  • Capponi, Sylvain
  • Mayaffre, Hadrien
  • Berthier, Claude
  • Paduan-Filho, Armando
  • Horvatić, Mladen
  • et al.
Abstract

Nuclear magnetic resonance (NMR) study of the high magnetic field (H) part of the Bose-Einstein condensed (BEC) phase of the quasi-onedimensional (quasi-1D) antiferromagnetic quantum spin-chain compound NiCl2-4SC(NH2)2 (DTN) was performed. We precisely determined the phase boundary, Tc(H), down to 40 mK; the critical boson density, n_c(Tc); and the absolute value of the BEC order parameter S_perp at very low temperature (T = 0.12 K). All results are accurately reproduced by numerical quantum Monte Carlo simulations of a realistic three-dimensional (3D) model Hamiltonian. Approximate analytical predictions based on the 1D Tomonaga-Luttinger liquid description are found to be precise for Tc(H), but less so for S_perp(H), which is more sensitive to the strength of 3D couplings, in particular close to the critical field. A mean-field treatment, based on the Hartree-Fock-Popov description, is found to be valid only up to n_c = 4% (T < 0.3 K), while for higher n_c boson interactions appear to modify the density of states.

Main Content
Current View