Evidence of quantum criticality in the doped Haldane system Y2BaNiO5

Abstract

Experimental bulk susceptibility X(T) and magnetization M(H,T) of the S=1-Haldane chain system doped with nonmagnetic impurities, Y2BaNi1-xZnxO5 (x=0.04,0.06,0.08), are analyzed. A numerical calculation for the low-energy spectrum of non-interacting open segments describes very well experimental data above 4 K. Below 4 K, we observe power-law behaviors, X(T)=T^-alpha and M(H,T)/T^(1-alpha)=f(alpha,(H/T)), with alpha (<1) depending on the doping concentration x.This observation suggests the appearance of a gapless quantum phase due to a broad distribution of effective couplings between the dilution-induced moments.

4 pages, 3 figures

References in corpus (7)

• Spin-Vacancy-Induced Long-Range Order in a New Haldane-Gap Antiferromagnet
• An Impurity Driven Phase Transition in the Antiferromagnetic Spin-1 Chain
• Percolation Transition in the random antiferromagnetic spin-1 chain
• Y NMR imaging of the staggered magnetization in doped Haldane chain Y(2)BaNi(1-x)Mg(x)O(5)
• Specific Heat of defects in the Haldane System Y_2BaNiO_5
• Electron Spin Resonance of defects in the Haldane System Y(2)BaNiO(5)
• Spin dynamics of hole doped Y2BaNiO5

Cited by in corpus (16)

• The density-matrix renormalization group
• Defects in correlated metals and superconductors
• Rare region effects at classical, quantum, and non-equilibrium phase transitions
• Dynamics and transport in random quantum systems governed by strong-randomness fixed points
• Strongly disordered spin ladders
• Permutation-Symmetric Multicritical Points in Random Antiferromagnetic Spin Chains
• Comparison of S=0 and S=1/2 Impurities in Haldane Chain Compound, $Y_{2}BaNi{O}_5$
• Spin thermal conductivity of the Haldane chain compound Y2BaNiO5
• Quantum Transport Through a Stretched Spin--1 Molecule
• Fully compensated Kondo effect for a two-channel spin S=1 impurity
• Magnetic responses of randomly depleted spin ladders
• Magnetization profiles and NMR spectra of doped Haldane chains at finite temperatures
• Dynamical magnetic anisotropy and quantum phase transitions in a vibrating spin-1 molecular junction
• Random interactions and spin-glass thermodynamic transition in the hole-doped Haldane system Y${}_{2-x}$Ca${}_x$BaNiO${}_5$
• Instability of the Haldane Phase: Roles of Charge Fluctuations and Hund's Coupling
• Gapless Haldane phase in realistic systems