Borla Umberto, Verresen Ruben, Grusdt Fabian, Moroz Sergej
Department of Physics, Technical University of Munich, 85748 Garching, Germany.
Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, München D-80799, Germany.
Phys Rev Lett. 2020 Mar 27;124(12):120503. doi: 10.1103/PhysRevLett.124.120503.
We investigate a quantum many-body lattice system of one-dimensional spinless fermions interacting with a dynamical Z_{2} gauge field. The gauge field mediates long-range attraction between fermions resulting in their confinement into bosonic dimers. At strong coupling we develop an exactly solvable effective theory of such dimers with emergent constraints. Even at generic coupling and fermion density, the model can be rewritten as a local spin chain. Using the density matrix renormalization group the system is shown to form a Luttinger liquid, indicating the emergence of fractionalized excitations despite the confinement of lattice fermions. In a finite chain we observe the doubling of the period of Friedel oscillations which paves the way towards experimental detection of confinement in this system. We discuss the possibility of a Mott phase at the commensurate filling 2/3.
我们研究了一个一维无自旋费米子与动态(Z_{2})规范场相互作用的量子多体晶格系统。规范场介导了费米子之间的长程吸引，导致它们被束缚成玻色子二聚体。在强耦合情况下，我们发展了一种具有涌现约束的此类二聚体的精确可解有效理论。即使在一般耦合和费米子密度下，该模型也可以重写为一个局域自旋链。使用密度矩阵重整化群方法表明，该系统形成了一个卢廷格液体，这表明尽管晶格费米子被束缚，但仍出现了分数化激发。在有限链中，我们观察到弗里德尔振荡周期加倍，这为该系统中束缚的实验检测铺平了道路。我们讨论了在填充率为(2/3)时出现莫特相的可能性。
