  Frustrated magnetic compounds, in particular low-dimensional, are topical
research due to persistent uncover of novel nontrivial quantum states and
potential applications. The problem of this field is that many important
results are scattered over the localized parameter ranges, while areas in
between still contain hidden interesting effects. We consider $J_1-J_2-J_3$
Heisenberg model on the square lattice and use the spherically symmetric
self-consistent approach for spin-spin Green's functions in "quasielastic"
approximation. We have found a new local order in spin liquids:
antiferromagnetic isotropical helices. On the structure factor we see circular
concentric dispersionless structures, while on any radial direction the
excitation spectrum has "roton" minima. That implies nontrivial magnetic
excitations and consequences in magnetic susceptibility and thermodynamics. On
the $J_1-J_2-J_3$ exchange parameters globe we discover a crossover between
antiferromagnetic-like local order and ferromagnetic-like; we find stripe-like
order in the middle. In fact, our "quasielastic" approach allows investigation
of the whole $J_1-J_2-J_3$ globe.
