Physics Department, Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-University Munich, 80333 Munich, Germany.
Phys Rev Lett. 2018 May 4;120(18):187001. doi: 10.1103/PhysRevLett.120.187001.
We present an exact ground state solution of a quantum dimer model introduced by Punk, Allais, and Sachdev [Quantum dimer model for the pseudogap metal, Proc. Natl. Acad. Sci. U.S.A. 112, 9552 (2015).PNASA60027-842410.1073/pnas.1512206112], which features ordinary bosonic spin-singlet dimers as well as fermionic dimers that can be viewed as bound states of spinons and holons in a hole-doped resonating valence bond liquid. Interestingly, this model captures several essential properties of the metallic pseudogap phase in high-T_{c} cuprate superconductors. We identify a line in parameter space where the exact ground state wave functions can be constructed at an arbitrary density of fermionic dimers. At this exactly solvable line the ground state has a huge degeneracy, which can be interpreted as a flat band of fermionic excitations. Perturbing around the exactly solvable line, this degeneracy is lifted and the ground state is a fractionalized Fermi liquid with a small pocket Fermi surface in the low doping limit.
我们提出了 Punk、Allais 和 Sachdev 引入的量子二聚体模型的精确基态解[Proc. Natl. Acad. Sci. U.S.A. 112, 9552 (2015).PNASA60027-842410.1073/pnas.1512206112]，其中包含普通玻色子自旋单重态二聚体以及可以看作是空穴掺杂共振价带液体中自旋子和空穴束缚态的费米子二聚体。有趣的是，该模型捕获了高温超导铜酸盐中金属赝能隙相的几个基本特性。我们在费米子二聚体任意密度的参数空间中确定了一条精确解基态波函数可以构建的线。在这条精确可解的线上，基态具有巨大的简并度，可以解释为费米子激发的平带。在精确可解线周围微扰，这种简并度被解除，基态是分数化费米液体，在低掺杂极限下具有小口袋费米面。
