Phase diagram of a frustrated two-dimensional J 1-J 2-J 3 quantum antiferromagnet: An approach based on spherically symmetric green’s functions

Magnetic spiral order in the square-lattice spin system (CuBr)Sr2Nb3O10

“…see [20,26] for calculational details and the cumbersome expressions for F q and the spin excitations spectrum ω q (both -T -depending). For J 1 − J 2 − J 3 model the Green's function G(q, ω, T ) involves the correlators c r for FIG.…”

Thermodynamic properties of the 2D frustrated Heisenberg model for the entire J1–J2 circle

“…Note that the third exchange interaction J 3 being added to the model changes the LRO picture qualitatively -the helical LRO becomes possible. In the J 1 − J 2 − J 3 model the condensate peak point in the structure factor can be located not only at Γ, Q, or X, but also at arbitrary incommensurate point on the side or diagonal of the Brillouin zone [7,46,55,56,60].…”

“…The tuning in SSSA is commonly made via different manipulations with vertex corrections [7,31,35,36,48,49,52,[54][55][56][57][58][59]62] or accounting for complex structure of the Green's function, that is, considering the polarization operator (in particular, accounting for damping of spin excitations) [7,55,56]. All such complications obviously affect the results.…”

“…In the J 1 − J 2 − J 3 model the condensate peak point in the structure factor can be located not only at Γ, Q, or X, but also at arbitrary incommensurate point on the side or diagonal of the Brillouin zone [7,46,55,56,60].…”

“…Let us also mention that SSSA has been applied to another lattice geometry, S > 1/2 [53], the systems with the anisotropic spin exchange -iron pnictides AFe 2 As 2 (A = Ca, Sr, Ba) - [54] and to 2D J 1 -J 2 -J 3 model [7,55,56].…”