Title: THERE IS LIFE IN THE OLD HORSE YET OR WHAT ELSE WE CAN LEARN STUDYING SPIN-1/2 XY CHAINS
Author(s): O.Derzhko (Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011 Lviv, Ukraine; Chair of Theoretical Physics, Ivan Franko National University of Lviv, 12 Drahomanov Street, 79005 Lviv, Ukraine)

We review some recent results on statistical mechanics of the one-dimensional spin-$\frac{1}{2}$ $XY$ systems paying special attention to the dynamic and thermodynamic properties of the models with Dzyaloshinskii-Moriya interaction, correlated disorder, and regularly alternating Hamiltonian parameters.

Key words: spin-$\frac{1}{2}$ $XY$ chains, Dzyaloshinskii-Moriya interaction, correlated disorder, magnetization plateaus, spin-Peierls instability
PACS: 75.10.-b