Evolution of the ESR absorption in a strong-leg spin ladder magnet (C7H10N2)2CuBr4 (abbreviated as DIMPY) is studied from 300K to 400mK. Temperature dependence of the ESR relaxation follows a staircase of crossovers between different relaxation regimes. We ague that the main mechanism of ESR line broadening in DIMPY is uniform Dzyaloshinskii-Moria interaction (∣D∣=0.20K) with an effective longitudinal component along an exchange bond of Cu ions within the legs resulting from the low crystal symmetry of DIMPY and nontrivial orbital ordering. The same Dzyaloshinskii-Moriya interaction results in the lifting of the triplet excitation degeneracy, revealed through the weak splitting of the ESR absorption at low temperatures.
@article{arxiv.1507.02503,
title = {ESR study of the spin ladder with uniform Dzyaloshinskii-Moria interaction},
author = {V. N. Glazkov and M. Fayzullin and Y. Krasnikova and G. Skoblin and D. Schmidiger and S. Mühlbauer and A. Zheludev},
journal= {arXiv preprint arXiv:1507.02503},
year = {2016}
}