Microscopic evolution of doped Mott insulators from polaronic metal to Fermi liquid
Microscopic evolution of doped Mott insulators from polaronic metal to Fermi liquid
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DOI：
10.1126/science.abe7165
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发表时间：
2020-09
期刊：
影响因子：
56.9
通讯作者：
J. Koepsell;Dominik Bourgund;P. Sompet;Sarah Hirthe;A. Bohrdt;Yao Wang;F. Grusdt;E. Demler;G. Salomon;C. Gross;I. Bloch
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文献类型：
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作者：
J. Koepsell;Dominik Bourgund;P. Sompet;Sarah Hirthe;A. Bohrdt;Yao Wang;F. Grusdt;E. Demler;G. Salomon;C. Gross;I. Bloch
描述 从极化子到费米液体 铜酸盐中的超导性是通过用空穴或电子掺杂反铁磁“母”态而出现的。随着掺杂的增加，反铁磁性让位于非常规超导性，系统最终变成费米液体。科普塞尔等人。使用困在光学晶格中的冷、强相互作用的锂 6 原子模拟了这一过程。尽管在实验可用的温度下尚未达到等效的有序相，但研究人员能够测量各种空穴掺杂范围内的多点自旋和空穴相关性。这些相关器随掺杂的演变揭示了从极化状态到费米液体的交叉。 —JS 光学晶格中强相互作用的锂 6 原子在大空穴掺杂范围内成像，以揭示交叉。二维莫特绝缘体中反铁磁性和空穴运动之间的竞争是从异常金属到传统费米液体的掺杂依赖性转变的核心。我们在冷原子量子模拟器上观察到费米-哈伯德系统中的这种交叉，并揭示了在超交换能附近的温度下增加掺杂后自旋和空穴之间的多点相关性的转变。此外，传统的可观测值，例如自旋敏感性，是根据系统的微观快照计算的。从磁极化子状态开始，我们发现该系统演变成费米液体，具有不相称的磁涨落和根本改变的相关性。空穴掺杂量约为 30% 时完成交叉。我们的工作对理论方法进行了基准测试，并讨论了与低温现象的可能联系。
Description From polarons to a Fermi liquid Superconductivity in the cuprates emerges by doping an antiferromagnetic “parent” state with holes or electrons. With increased doping, antiferromagnetism gives way to unconventional superconductivity, and the system eventually becomes a Fermi liquid. Koepsell et al. simulated this progression using cold, strongly interacting lithium-6 atoms trapped in an optical lattice. Although the equivalent ordered phases are not yet reachable at the experimentally available temperatures, the researchers were able to measure multipoint spin and hole correlations over a wide range of hole doping. The evolution of these correlators with doping revealed a crossover from a polaronic regime to a Fermi liquid. —JS Strongly interacting lithium-6 atoms in an optical lattice were imaged across a large hole doping range to reveal a crossover. The competition between antiferromagnetism and hole motion in two-dimensional Mott insulators lies at the heart of a doping-dependent transition from an anomalous metal to a conventional Fermi liquid. We observe such a crossover in Fermi-Hubbard systems on a cold-atom quantum simulator and reveal the transformation of multipoint correlations between spins and holes upon increasing doping at temperatures around the superexchange energy. Conventional observables, such as spin susceptibility, are furthermore computed from the microscopic snapshots of the system. Starting from a magnetic polaron regime, we find the system evolves into a Fermi liquid featuring incommensurate magnetic fluctuations and fundamentally altered correlations. The crossover is completed for hole dopings around 30%. Our work benchmarks theoretical approaches and discusses possible connections to lower-temperature phenomena.