The single-Q state of chromium

4f-local magnetic moments in the metals and alloys with SDW-instability

“…It should be noted that in the real metals the wave vector Q of SDW does not coincide with the mean nesting vector Q. The difference occurs because the free energy minimum which determines Q is a compromise between the contributions from different parts of non-ideal nested Fermi surfaces (parameters /11,2 k ) =A 0) [15]. For simplicity we assume that Q = Q and then all our results are equivalent for both (helical and sine) cases.…”

Layered pnictide-oxide Na2Ti2Pn2O (Pn=As, Sb): a candidate for spin density waves

“…As presented above, there are two independent and orthogonal but equivalent nesting vectors Q 1 = ( π a , 0, 0) and Q 2 = (0, π a , 0). Thus a possible linearly polarized spin density wave will be either a single-Q state described by M cos( Q • R + ϕ) on the Ti-Ti square lattice ( R being a lattice site vector, M magnetization vector, and ϕ phase factor) with a wavevector Q equal to either Q 1 or Q 2 , or a double-Q state described by M cos( [34][35][36][37][38]. Accordingly, we elaborately constructed several kinds of magnetic orders.…”

Universal Spin-Flip Transition in Itinerant Antiferromagnets

“…From the structure of the poles it is already obvious that the perpendicular field is not in direct competition with the SDW. None of the quasiparticle poles given in (10) can be set to zero no matter how large the magnetic field is. This indicates that the magnetic field cannot melt the SDW.…”

“…The itinerant character of AFM and the relevance of the SDW picture in cromium are firmly established experimentally [3,4]. However, despite several decades of intense theoretical work which led to the construction of a successful microscopic SDW model for cromium [2,[5][6][7][8][9][10][11][12], there is a surprising aspect of the AFM behavior in this material which escapes any microscopic understanding so far. It is the famous spinflip (SF) transition as a function of temperature for which there are only phenomenological accounts within a Landau framework [4,[13][14][15].…”