Topological polarons, quasiparticle invariants, and their detection in one-dimensional symmetry-protected phases
Topological polarons, quasiparticle invariants, and their detection in one-dimensional symmetry-protected phases
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DOI：
10.1103/physrevb.100.075126
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发表时间：
2019-08-12
影响因子：
3.7
通讯作者：
Demler, E. A.
中科院分区：
文献类型：
--
作者：
Grusdt, F.;Yao, N. Y.;Demler, E. A.
在对称性的存在下，一维量子系统可以表现出拓扑有序，在许多情况下，这可以用多体几何Zak或Berry相的量子化值来表征。我们证明了这种拓扑ZAK相与系统中初级准粒子激发的ZAK相直接相关。通过考虑不同的系统，我们建立了许多不同的相互作用相之间的联系，包括SU-Schrieffer-Heeger模型、p波拓扑超导体和Haldane链。最重要的是，与这种系统的基态相关的主体多体ZAK相相比，与准粒子激发相关的拓扑不变量(在这个基态之上)显示了一条更自然的直接实验检测的途径。为此，我们在最近工作的基础上[F.Grusdt等人，NAT。交警。7,11994(2016)]，并证明了移动量子杂质可以与拉姆齐干涉测量和布洛赫振荡相结合，直接测量这些准粒子拓扑不变量。最后，讨论和分析了我们的协议在超冷原子系统中用于二聚化Mott绝缘子的具体实验实现。
In the presence of symmetries, one-dimensional quantum systems can exhibit topological order, which in many cases can be characterized by a quantized value of the many-body geometric Zak or Berry phase. We establish that this topological Zak phase is directly related to the Zak phase of an elementary quasiparticle excitation in the system. By considering various systems, we establish this connection for a number of different interacting phases including the Su-Schrieffer-Heeger model, p-wave topological superconductors, and the Haldane chain. Crucially, in contrast to the bulk many-body Zak phase associated with the ground state of such systems, the topological invariant associated with quasiparticle excitations (above this ground state) exhibits a more natural route for direct experimental detection. To this end, we build upon recent work [F. Grusdt, et al., Nat. Commun. 7, 11994 (2016)] and demonstrate that mobile quantum impurities can be used, in combination with Ramsey interferometry and Bloch oscillations, to directly measure these quasiparticle topological invariants. Finally, a concrete experimental realization of our protocol for dimerized Mott insulators in ultracold atomic systems is discussed and analyzed.