论文标题
双扭式双层石墨烯中的量子件启用激素冷凝物
Quantum-metric-enabled exciton condensate in double twisted bilayer graphene
论文作者
论文摘要
平面系统是一个有前途的平台，用于实现具有自发对称性的异国情调的集体基础状态，因为电子电子相互作用在动能上占主导地位。引起激子冷凝物（EC）追赶的集体基础状态。但是，在平面系统中，其他集体基础状态可以与EC相竞争，并且对热和量子波动的效果的常规处理预测EC相应该不稳定。 Here, using double twisted bilayer graphene (TBLG) heterostructures as an example, we show that for realistic interaction strengths the EC phase is favored with respect to other TBLG's phases -- orbital magnetism and superconductivity -- when the TBLGs have opposite doping, and that the quantum metric of the Bloch wave functions stabilizes the EC, reversing the conclusion that would be drawn from the conventional approach in which quantum公制贡献被忽略了。我们的结果表明，量子公制在确定具有平坦带的系统形成的双层中激子冷凝物的稳定性中起着关键作用。
Flat-band systems are a promising platform for realizing exotic collective ground states with spontaneously broken symmetry because the electron-electron interactions dominate over the kinetic energy. A collective ground state of particular interest is the chased after exciton condensate (EC). However, in flat band systems other collective ground states can compete with an EC phase, and the conventional treatment of the effect of thermal and quantum fluctuations predicts the EC phase should be unstable. Here, using double twisted bilayer graphene (TBLG) heterostructures as an example, we show that for realistic interaction strengths the EC phase is favored with respect to other TBLG's phases -- orbital magnetism and superconductivity -- when the TBLGs have opposite doping, and that the quantum metric of the Bloch wave functions stabilizes the EC, reversing the conclusion that would be drawn from the conventional approach in which quantum metric contributions are neglected. Our results suggest that the quantum metric plays a critical role in determining the stability of exciton condensates in double layers formed by systems with flat-bands.
