Quantum dynamics of a domain wall in a quasi one-dimensional $XXZ$ ferromagnet

Pavel Tikhonov, Efrat Shimshoni

We derive an effective low-energy theory for a ferromagnetic $(2N+1)$-leg spin-$\frac{1}{2}$ ladder with strong $XXZ$ anisotropy $\left|J_{\parallel}^z\right|\ll \left|J_{\parallel…