Double-layer quantum systems are promising platforms for realizing novel quantum phases. Here, we report a study of quantum oscillations (QOs) in a weakly coupled double-layer system composed of a large-angle twisted-double-bilayer graphene (TDBG). We quantify the interlayer coupling strength by measuring the interlayer capacitance from the QOs pattern at low temperatures, revealing electron–hole asymmetry. At high temperatures when SdHOs are thermally smeared, we observe resistance peaks when Landau levels (LLs) from two moiré minivalleys are aligned, regardless of carrier density; eventually, it results in a 2-fold increase of oscillating frequency in D, serving as compelling evidence of the magneto-intersub-band oscillations (MISOs) in double-layer systems. The temperature dependence of MISOs suggests that electron–electron interactions play a crucial role and the scattering times obtained from MISO thermal damping are correlated with the interlayer coupling strength. Our study reveals intriguing interplays among Landau quantization, moiré band structure, and scatterings.

中文翻译：

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弱耦合莫尔超晶格中朗道量子化和谷间散射的相互作用

双层量子系统是实现新型量子相的有前途的平台。在这里，我们报告了由大角度扭曲双层石墨烯（TDBG）组成的弱耦合双层系统中的量子振荡（QO）的研究。我们通过测量低温下 QO 图案的层间电容来量化层间耦合强度，揭示电子-空穴不对称性。在高温下，当 SdH2O 被热涂抹时，无论载流子密度如何，当两个莫尔小谷的朗道能级 (LL) 对齐时，我们都会观察到电阻峰值；最终，它导致D中的振荡频率增加了 2 倍，成为双层系统中磁子带间振荡 (MISO) 的有力证据。 MISO 的温度依赖性表明电子-电子相互作用起着至关重要的作用，并且从 MISO 热阻尼获得的散射时间与层间耦合强度相关。我们的研究揭示了朗道量化、莫尔带结构和散射之间有趣的相互作用。