论文标题
沮丧的旋转梯子中的互动三倍：bicu $ _2 $ po $ _6 $中的绑定和衰减
Interacting triplons in frustrated spin ladders: Binding and decay in BiCu$_2$PO$_6$
论文作者
论文摘要
在过去的十年中，建立BICU $ _2 $ po $ _6 $中丰富的自旋动力学的综合模型一直是一个挑战。非弹性中子散射实验表明，其基本三角素是非脱位的，表明存在显着的各向异性自旋耦合。已经发现了三倍衰减的证据，发现分散的两个突出的低迷是一种解释。由于单一三元杂交与两轨散射状态的连续体杂交引起的水平排斥已被提出为解释。我们表明，这个概念可能解释了较高能量下的疲软的衰退，但在低能量下最明显的衰退失败了。反过来，我们提供了证据表明，这种衰退是基本上是单重线特征的两道束缚状态的签名，指向三龙 - 三层相互作用是该示例性系统中自旋动力学的第二个关键成分。
Establishing a comprehensive model of the rich spin dynamics in BiCu$_2$PO$_6$ has been a challenge over the last decade. Inelastic neutron scattering experiments revealed that its elementary triplons are non-degenerate showing the existence of significant anisotropic spin couplings. Evidence for triplon decay into two triplons has been found, but two prominent downturns in the dispersions eluded an explanation. Level repulsion due to hybridization of single triplons with the continuum of two-triplon scattering states has been proposed as explanation. We show that this concept may explain the weak downturn at higher energies, but fails for the most pronounced downturn at lower energy. In turn, we provide evidence that this downturn is the signature of a two-triplon bound state of essentially singlet character pointing to triplon-triplon interaction as the second crucial ingredient of the spin dynamics in this exemplary system.
