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Larionov, I. A.

doi:10.1103/physrevb.69.214525

Cited by 17 publications

(32 citation statements)

References 73 publications

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“…In summary, in the analytic approximation considered here, the quantity χ 2D (ω) (and therefore the scaling functionf(ω/T )) is determined at ω J by expression (23) and has the form of a step function that vanishes at ω ∼ Δ and is smeared over the width ∼ γ. But the measurements at helium temperatures in weakly doped cuprates show a deviation from that behavior: at the lowest frequencies, χ 2D (ω) starts increasing and only then vanishes [43]- [45].…”

Section: Scaling Behavior Of Spin Susceptibilitymentioning

confidence: 98%

Frustrated quantum two-dimensional J 1-J 2-J 3 antiferromagnet in a spherically symmetric self-consistent approach

2011

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In the framework of a spherically symmetric self-consistent approach to two-time retarded spin-spin Green's functions, we develop the theory of a two-dimensional frustrated J1-J2-J3 quantum S=1/2 antiferromagnet. We show that taking the damping of spin fluctuations into account is decisive in forming both the spin-liquid state and the state with long-range order. In particular, the existence of damping allows explaining the scaling behavior of the susceptibility χ(q, ω) of the CuO2 cuprate plane, the behavior of the spin spectrum in the two-plane case, and the occurrence of an incommensurable χ(q, ω) peak. In the case of the complete J1-J2-J3 model, in a single analytic approach, we find continuous transitions between three phases with long-range order ("checkerboard," stripe, and helical (q, q) phases) through the spin-liquid state. We obtain good agreement with cluster computations for the J1-J2-J3 model and agreement with the neutron scattering data for the J1-J2 model of cuprates. the occurrence of a spin gap Δ at an arbitrarily low temperature T = 0 into account and describing the long-range order (LRO) at T = 0. It is known that as the doping level increases in two-dimensional AFMs, the spin correlation length decreases. Introducing frustration leads to a similar behavior. It is obvious that there is no direct correspondence between doping and frustration. Nevertheless, an increase in frustration can be qualitatively treated as an increase in x. It is believed that the CuO 2 cuprate plane corresponds to a nonvanishing frustration even at x = 0 [10], and the purely spin model has been used many times to analyze the spin response of the doped CuO 2 plane (see, e.g., [11]).Here, in a spherically symmetric self-consistent approach (SSSA) [7], [8], [12], [13], we study the J 1 -J 2 -J 3 model in its different versions: the J 1 model (J 2 = J 3 = 0); the J 1 -J 2 model (J 3 = 0), which is the case most studied in cluster computations; and the J 1 -J 2 -J 3 model-the complete model, which exhibits a series of phases. Our treatment is based on the two-time temperature spin Green's function G q (ω) [14].In contrast to spin-wave two-sublattice approaches, the SSSA states both with and without LRO are singlet, the Marshall and Mermin-Wagner theorems are satisfied automatically, and the spin SU (2) and translation symmetries are preserved (we do not consider the so-called box and columnar states). In particular, this implies that the averaged spin operator at a site is equal to zero, S α n = 0, α = x, y, z, and that the spin correlators C r = S α n+r S α n are independent of the position of the site n. The method allows finding the microscopic characteristics that cannot be extracted from cluster computations, such as the spin-excitation spectra ω q , the dependence Δ(T ) and its position, and the explicit form of the function χ(q, ω, T ). The main difference between our method and the standard realization of the SSSA is that we go beyond the mean field approximation by introducing damping into the expression for the s...

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Section: Scaling Behavior Of Spin Susceptibilitymentioning

confidence: 98%

Frustrated quantum two-dimensional J 1-J 2-J 3 antiferromagnet in a spherically symmetric self-consistent approach

2011

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“…For low temperature behavior we use the expression, resulting in effective correlation length ξ ef f , given by 17,24,26…”

Section: Basic Relationsmentioning

confidence: 99%

“…, valid for carrier free or lightly doped systems. 17,22 In the best fit of ξ ef f to experimental data 26,27 the relation ξ 0 = a/n ξ x is most suited 11,17 which one may attribute to stripe picture, where n ξ =2 for x ≤0.05 and n ξ =1 near optimal (x ≈0.15) doping. The results of the calculations are summarized in Table I.…”

Section: Basic Relationsmentioning

confidence: 99%

“…The contribution from spin diffusion (small wave vectors k < 1/ξ ef f ) may be calculated from general physical grounds, namely, the linear response theory, hydrodynamics, and fluctuation-dissipation theorem 29 (see also Ref. 17)…”

Section: Plane Oxygen Nuclear Spin-lattice Relaxationmentioning

confidence: 99%

“…35 and carrier free insulating 2DHAF, e.g., YBa 2 Cu 3 O 6.15 and La 2 CuO 4 . 15 The spin diffusive contribution 17 (1/T 1 ) Dif f to plane oxygen nuclear spin-lattice relaxation rate 17 (1/T 1 ) cannot be excluded solely by failure to detect 16 the changes in 17 (1/T 1 ) by varying the nuclear magnetic resonance (NMR) fre-quency ω since 17 (1/T 1 ) Dif f varies rather weakly 17 with ω.…”

Section: Introductionmentioning

confidence: 99%

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Paramagnonlike excitations and spin diffusion in magnetic resonance studies of copper oxide superconductors

Larionov

2007

Phys. Rev. B

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The relaxation function theory for a doped two-dimensional Heisenberg antiferromagnetic system in the paramagnetic state for all wave vectors through the Brillouin zone is presented in view of low frequency response of high-Tc copper oxide superconductors. We deduced the regions of long lifetime [T < ∼ 400(1−4x) K] and "overdamped" [T > ∼ 700(1−4x) K] paramagnonlike excitations in the temperature (T )-doping index (x) phase diagram from plane oxygen nuclear spin-lattice relaxation rate 17 (1/T1) data in up to optimally doped La2−xSrxCuO4 thus providing the regimes for the spin wave concept and the "overdamped" mode.

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Theory for the Gaussian Component of the 63Cu Nuclear Spin-Echo Decay Rate 1/T 2G in La2−x Sr x CuO4

Larionov

2014

Appl Magn Reson

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Spin dynamics in lightly dopedLa2−xSrxCuO4: Relaxation function within the
I. A. Larionov
¹

Cited by 17 publications

References 73 publications

Frustrated quantum two-dimensional J 1-J 2-J 3 antiferromagnet in a spherically symmetric self-consistent approach

Frustrated quantum two-dimensional J 1-J 2-J 3 antiferromagnet in a spherically symmetric self-consistent approach

Paramagnonlike excitations and spin diffusion in magnetic resonance studies of copper oxide superconductors

Theory for the Gaussian Component of the 63Cu Nuclear Spin-Echo Decay Rate 1/T 2G in La2−x Sr x CuO4

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Spin dynamics in lightly dopedLa2−xSrxCuO4: Relaxation function within theI. A. Larionov1

Cited by 17 publications

References 73 publications

Frustrated quantum two-dimensional J 1-J 2-J 3 antiferromagnet in a spherically symmetric self-consistent approach

Frustrated quantum two-dimensional J 1-J 2-J 3 antiferromagnet in a spherically symmetric self-consistent approach

Paramagnonlike excitations and spin diffusion in magnetic resonance studies of copper oxide superconductors

Theory for the Gaussian Component of the 63Cu Nuclear Spin-Echo Decay Rate 1/T 2G in La2−x Sr x CuO4

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Product

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About

Spin dynamics in lightly dopedLa2−xSrxCuO4: Relaxation function within the
I. A. Larionov
¹