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- W2015241999 abstract "We have studied the static and dynamic magnetic properties of two-dimensional (2D) and quasi-two-dimensional, spin-S, quantum Heisenberg antiferromagnets diluted with spinless vacancies. Using spin-wave theory and the T-matrix approximation we have calculated the staggered magnetization $M(x,T),$ the neutron scattering dynamical structure factor $mathcal{S}(mathbf{k},ensuremath{omega}),$ the 2D magnetic correlation length $ensuremath{xi}(x,T)$ and, for the quasi- (2D) case, the N'eel temperature ${T}_{N}(x).$ We find that in two dimensions a hydrodynamic description of excitations in terms of spin waves breaks down at wavelengths larger than $l/aensuremath{sim}{e}^{ensuremath{pi}/4x},$ x being the impurity concentration and a the lattice spacing. We find signatures of localization associated with the scale l, and interpret this scale as the localization length of magnons. The spectral function for momenta ${a}^{ensuremath{-}1}ensuremath{gg}kensuremath{gg}{l}^{ensuremath{-}1}$ consists of two distinct parts: (i) a damped quasiparticle peak at an energy ${c}_{0}kensuremath{gtrsim}ensuremath{omega}ensuremath{gg}{ensuremath{omega}}_{0},$ with abnormal damping ${ensuremath{Gamma}}_{k}ensuremath{sim}x{c}_{0}k,$ where ${ensuremath{omega}}_{0}ensuremath{sim}{c}_{0}{l}^{ensuremath{-}1},$ ${c}_{0}$ is the bare spin-wave velocity; and (ii) a non-Lorentian localization peak at $ensuremath{omega}ensuremath{sim}{ensuremath{omega}}_{0}.$ For $kensuremath{lesssim}{l}^{ensuremath{-}1}$ these two structures merge, and the spectrum becomes incoherent. The density of states acquires a constant term, and exhibits an anomalous peak at $ensuremath{omega}ensuremath{sim}{ensuremath{omega}}_{0}$ associated with low-energy localized excitations. These anomalies lead to a substantial enhancement of the magnetic specific heat ${C}_{M}$ at low temperatures. Although the dynamical properties are significantly modified, we show that $D=2$ is not the lower critical dimension for this problem. We find that at small x the average staggered magnetization at the magnetic site is $M(x,0)ensuremath{simeq}Sensuremath{-}ensuremath{Delta}ensuremath{-}Bx,$ where $ensuremath{Delta}$ is the zero-point spin deviation and $Bensuremath{simeq}0.21$ is independent of the value of S; the N'eel temperature ${T}_{N}(x)ensuremath{simeq}(1ensuremath{-}{A}_{s}x) {T}_{N}(0),$ where ${A}_{s}=ensuremath{pi}ensuremath{-}2/ensuremath{pi}+B/(Sensuremath{-}ensuremath{Delta})$ is weakly S dependent. Our results are in quantitative agreement with recent Monte Carlo simulations and experimental data for $S=1/2,$ 1, and 5/2. In our approach long-range order persists up to a high concentration of impurities ${x}_{c}$ which is above the classical percolation threshold ${x}_{p}ensuremath{approx}0.41.$ This result suggests that long-range order is stable at small x, and can be lost only around $xensuremath{simeq}{x}_{p}$ where approximations of our approach become invalid." @default.
- W2015241999 created "2016-06-24" @default.
- W2015241999 creator A5001361375 @default.
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- W2015241999 date "2002-02-11" @default.
- W2015241999 modified "2023-09-25" @default.
- W2015241999 title "Diluted quantum antiferromagnets: Spin excitations and long-range order" @default.
- W2015241999 cites W1491431233 @default.
- W2015241999 cites W1516977029 @default.
- W2015241999 cites W1563962064 @default.
- W2015241999 cites W1580553528 @default.
- W2015241999 cites W1616206703 @default.
- W2015241999 cites W1960667724 @default.
- W2015241999 cites W1963849632 @default.
- W2015241999 cites W1966318592 @default.
- W2015241999 cites W1967336145 @default.
- W2015241999 cites W1968307272 @default.
- W2015241999 cites W1970286945 @default.
- W2015241999 cites W1972551285 @default.
- W2015241999 cites W1977568188 @default.
- W2015241999 cites W1981447860 @default.
- W2015241999 cites W1982927504 @default.
- W2015241999 cites W1985411599 @default.
- W2015241999 cites W1986906353 @default.
- W2015241999 cites W1987934374 @default.
- W2015241999 cites W1990262287 @default.
- W2015241999 cites W1990932576 @default.
- W2015241999 cites W1992543295 @default.
- W2015241999 cites W1993022044 @default.
- W2015241999 cites W1993180754 @default.
- W2015241999 cites W1993617204 @default.
- W2015241999 cites W1993648391 @default.
- W2015241999 cites W1995783744 @default.
- W2015241999 cites W1999024830 @default.
- W2015241999 cites W2001942003 @default.
- W2015241999 cites W2004915137 @default.
- W2015241999 cites W2005488437 @default.
- W2015241999 cites W2005536981 @default.
- W2015241999 cites W2006232082 @default.
- W2015241999 cites W2006728861 @default.
- W2015241999 cites W2009455826 @default.
- W2015241999 cites W2010974419 @default.
- W2015241999 cites W2016559897 @default.
- W2015241999 cites W2019575437 @default.
- W2015241999 cites W2022960368 @default.
- W2015241999 cites W2026365189 @default.
- W2015241999 cites W2031165376 @default.
- W2015241999 cites W2033655195 @default.
- W2015241999 cites W2037370507 @default.
- W2015241999 cites W2037729767 @default.
- W2015241999 cites W2040006353 @default.
- W2015241999 cites W2040331307 @default.
- W2015241999 cites W2042788319 @default.
- W2015241999 cites W2043314260 @default.
- W2015241999 cites W2046313335 @default.
- W2015241999 cites W2051325306 @default.
- W2015241999 cites W2051494409 @default.
- W2015241999 cites W2057460263 @default.
- W2015241999 cites W2057847608 @default.
- W2015241999 cites W2063846558 @default.
- W2015241999 cites W2065122697 @default.
- W2015241999 cites W2068422510 @default.
- W2015241999 cites W2069306213 @default.
- W2015241999 cites W2071394313 @default.
- W2015241999 cites W2072143550 @default.
- W2015241999 cites W2073574320 @default.
- W2015241999 cites W2075013807 @default.
- W2015241999 cites W2078139704 @default.
- W2015241999 cites W2079921044 @default.
- W2015241999 cites W2091299566 @default.
- W2015241999 cites W2094051197 @default.
- W2015241999 cites W2095499503 @default.
- W2015241999 cites W2106883211 @default.
- W2015241999 cites W2117332517 @default.
- W2015241999 cites W2162676140 @default.
- W2015241999 cites W2264002775 @default.
- W2015241999 cites W2299225523 @default.
- W2015241999 cites W2399117857 @default.
- W2015241999 cites W291443582 @default.
- W2015241999 cites W2951679583 @default.
- W2015241999 cites W3102085447 @default.
- W2015241999 doi "https://doi.org/10.1103/physrevb.65.104407" @default.
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