Fraxanet Joana, González-Cuadra Daniel, Pfau Tilman, Lewenstein Maciej, Langen Tim, Barbiero Luca
ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain.
Center for Quantum Physics, University of Innsbruck, 6020 Innsbruck, Austria.
Phys Rev Lett. 2022 Jan 28;128(4):043402. doi: 10.1103/PhysRevLett.128.043402.
The combination of topology and quantum criticality can give rise to an exotic mix of counterintuitive effects. Here, we show that unexpected topological properties take place in a paradigmatic strongly correlated Hamiltonian: the 1D extended Bose-Hubbard model. In particular, we reveal the presence of two distinct topological quantum critical points with localized edge states and gapless bulk excitations. Our results show that the topological critical points separate two phases, one topologically protected and the other topologically trivial, both characterized by a long-range ordered string correlation function. The long-range order persists also at the topological critical points and explains the presence of localized edge states protected by a finite charge gap. Finally, we introduce a superresolution quantum gas microscopy scheme for dipolar dysprosium atoms, which provides a reliable route towards the experimental study of topological quantum critical points.
拓扑结构与量子临界性的结合能够产生一系列违反直觉效应的奇特组合。在此，我们表明在一个典型的强关联哈密顿量——一维扩展玻色 - 哈伯德模型中出现了意想不到的拓扑性质。特别地，我们揭示了存在两个具有局域化边缘态和无隙体态激发的不同拓扑量子临界点。我们的结果表明，拓扑临界点将两个相分开，一个是拓扑保护相，另一个是拓扑平凡相，两者都由长程有序的弦关联函数表征。长程有序在拓扑临界点也持续存在，并解释了由有限电荷能隙保护的局域化边缘态的存在。最后，我们为偶极镝原子引入了一种超分辨率量子气体显微镜方案，这为拓扑量子临界点的实验研究提供了一条可靠途径。
