Phonon-Pumped Spin-Wave Instabilities
Phonon-Pumped Spin-Wave Instabilities
复制标题
声子泵浦自旋波不稳定性
DOI：
10.1103/physrevlett.13.614
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发表时间：
1964
影响因子：
8.6
通讯作者：
F. Morgenthaler
中科院分区：
文献类型：
--
作者：
H. Matthews;F. Morgenthaler
具有最小阈值的自旋波对在工作空间中的位置将严重依赖于Hp的值。% e将参考图1，其中我们设置了40z=-yHz,=-y4wM和（u~=[u）~(~~+(uM))'”。当Hp值使得QcL) p明显高于自旋波带的“顶部”时[图1 (a)]，只有当两个伴星的k都很大时，能量和动量才可以守恒。通过比较，k~= 0和k，= k，。模态是简并的，适用式（12）。最小阈值出现在4'= &~。对于Hp值使得~ up位于自旋波带内[图1 (b)]，可能存在k较小的非简并对（a-a', c-c', d-d'），也可能存在de-
The position in wk space of the spin-wave pair with the minimum threshold will depend critically on the valueof Hp.% e will refer to Fig. 1, for which we have set 40z=-yHz,=-y4wM, and (u~=[u)~(~~+(uM))'". For values of Hp such that QcL) p lies appreciably above the" top" of the spin-wave band [Fig. 1 (a)], energy and momentum can be conserved only is both partners have large k. By comparison, k~= 0 and k,= k,. The modes are degenerate and Eq.(12) is applicable. The minimum threshold occurs for 4'= &~. For values of Hp such that~ up, lies within the spin-wave band [Fig. 1 (b)), nondegenerate pairs with small k (a-a', c-c', d-d') are possible, as well as de-