Vienna Center for Quantum Science, Universität Wien, Boltzmanngasse 5, A-1090 Wien, Austria.
Phys Rev Lett. 2013 Jul 12;111(2):020402. doi: 10.1103/PhysRevLett.111.020402. Epub 2013 Jul 9.
We introduce a variational method for calculating dispersion relations of translation invariant (1+1)-dimensional quantum field theories. The method is based on continuous matrix product states and can be implemented efficiently. We study the critical Lieb-Liniger model as a benchmark and excellent agreement with the exact solution is found. Additionally, we observe solitonic signatures of Lieb's type II excitation. In addition, a nonintegrable model is introduced where a U(1)-symmetry breaking term is added to the Lieb-Liniger Hamiltonian. For this model we find evidence of a nontrivial bound-state excitation in the dispersion relation.
我们介绍了一种计算平移不变（1+1）-维量子场论色散关系的变分方法。该方法基于连续矩阵乘积态，可以有效地实现。我们以临界李-林格模型为基准进行了研究，发现与精确解吻合得非常好。此外，我们还观察到了李的 II 型激发的孤子特征。此外，我们还引入了一个不可积模型，即在李-林格哈密顿量中添加 U(1)-对称破缺项。对于这个模型，我们在色散关系中发现了一个非平凡束缚态激发的证据。
