Magnetization profiles and NMR spectra of doped Haldane chains at finite temperatures

Abstract

Open segments of S=1 antiferromagnetic spin chains are studied at finite temperatures and fields using continuous time Quantum Monte Carlo techniques. By calculating the resulting magnetization profiles for a large range of chain lengths with fixed field and temperature we reconstruct the experimentally measured NMR spectrum of impurity doped Y${}_2$BaNi${}_{1-x}$Mg${}_x$O${}_5$. For temperatures above the gap the calculated NMR spectra are in excellent agreement with the experimental results, confirming the existence of $S=1/2$ excitations at the end of open S=1 chain segments. At temperatures below the gap, neglecting inter chain couplings, we still find well defined peaks in the calculated NMR spectra corresponding to the $S=1/2$ chain end excitations. At low temperatures, inter chain couplings could be important, resulting in a more complicated phase.

7 pages, 5 figures, minor corrections

References in corpus (7)

• Y NMR imaging of the staggered magnetization in doped Haldane chain Y(2)BaNi(1-x)Mg(x)O(5)
• Monte Carlo Study of Correlations in Quantum Spin Chains at Non-Zero Temperature
• The Two-Dimensional S=1 Quantum Heisenberg Antiferromagnet at Finite Temperatures
• $S=1/2$ Chain-Boundary Excitations in the Haldane Phase of 1D $S=1$ Systems
• Evidence of quantum criticality in the doped Haldane system Y2BaNiO5
• Electron Spin Resonance of defects in the Haldane System Y(2)BaNiO(5)
• Quantum Monte Carlo Study on Magnetization Processes

Cited by in corpus (9)

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• Magnetization and dimerization profiles of the cut two-leg spin ladder and spin-1 chain
• Comparison of S=0 and S=1/2 Impurities in Haldane Chain Compound, $Y_{2}BaNi{O}_5$
• Rabi oscillations of solitons in spin-chains: a new route to quantum computation and communication
• Impurity effects in coupled-ladder BiCu2PO6 studied by NMR and quantum Monte Carlo simulations
• Staggered magnetization and entanglement enhancement by magnetic impurities in $S=1/2$ spin chain
• NMR Response in quasi one-dimensional Spin-1/2 Antiferromagnets
• On-site magnetization in open antiferromagnetic chains: a classical analysis versus NMR experiments in a spin-1 compound
• Magnetic versus nonmagnetic doping effects on the magnetic ordering in the Haldane chain compound PbNi2V2O8