We present a combined experimental and theoretical study of twisted double bilayer graphene with twist angles between 1° and 1.35°. Consistent with moiré band structure calculations, we observe insulators at integer moiré band fillings one and three, but not two. An applied transverse electric field separates the first moiré conduction band from neighboring bands, and favors the appearance of correlated insulators at

,

, and

band filling. Insulating states at

and

band filling emerge only in a parallel magnetic field (

), whereas the resistivity at half band filling is weakly dependent on

. Our findings suggest that correlated insulators are favored when a moiré flat band is spectrally isolated, and are consistent with a mean-field picture in which insulating states are established by breaking both spin and valley symmetries at

and

band filling and valley polarization alone at

band filling.

我们提出了一种扭曲的双层双层石墨烯的实验和理论研究相结合的研究，其扭曲角在1°和1.35°之间。与莫尔带结构计算一致，我们观察到在整数莫尔带填充为1和3而不是2处的绝缘子。施加的横向电场将第一莫尔导带与相邻带分开，并有利于相关绝缘子出现在

，

， 和

乐队填充。处的绝缘状态

和

带填充仅在平行磁场中出现（

），而半带填充时的电阻率则弱依赖于

。我们的发现表明，当莫尔条纹平坦谱带被频谱隔离时，相关的绝缘体会受到青睐，并且与均值图片一致，在该图片中，通过破坏自旋和波谷对称性可建立绝缘状态

和

仅在

乐队填充。