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Theory of Nuclear Spin-Lattice Relaxation in La$_2$CuO$_4$ at High Temperatures

A. Sokol·E. Gagliano·S. Bacci
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Abstract

The problem of the nuclear spin-lattice relaxation in La$_2$CuO$_4$ is revisited in connection with the recent measurements of the NQR relaxation rate for temperatures up to $ 900\mbox{K} $ [T.\ Imai {\em et al.}, Phys.\ Rev.\ Lett., in press]. We use an approach based on the exact diagonalization for the Heisenberg model to calculate the short wavelength contribution to the relaxation rate in the high temperature region, $ T \! \agt \! J/2 $. It is shown that the spin diffusion accounts for approximately 10\% of the total relaxation rate at $900 \mbox{K} $ and would become dominant for $T\! >\! J$. The calculated $1/T_1$ is in good agreement with the experiment both in terms of the absolute value and temperature dependence.

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A. Sokol, E. Gagliano, S. Bacci. 1993-02-09. Theory of Nuclear Spin-Lattice Relaxation in La$_2$CuO$_4$ at High Temperatures. https://doi.org/10.1103/physrevb.47.14646

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