发表机构
State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Optoelectronics, Shanxi University; Collaborative Innovation Center of Extreme Optics, Shanxi University; Liaoning Academy of Materials; School of Physical Science and Technology, ShanghaiTech University; ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University; Hefei National Laboratory（山西大学光电研究所量子光学与量子光学器件国家重点实验室; 山西大学极端光学协同创新中心; 辽宁省材料研究院; 上海科技大学物理科学与技术学院; 上海科技大学拓扑物理实验室; 合肥国家实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在扭转MoS$_2$导带中观测到关联电子态及Pomeranchuk-like局域化，其可在100 K以上持续，揭示了半导体莫尔体系中的复杂电荷局域化行为。
AI 中文摘要
扭转过渡金属二硫化物（TMDs）已展现出丰富的新奇物理现象，然而迄今为止实验研究大多局限于其价带（p型掺杂）。在此，我们展示了近AA堆叠的扭转双层MoS$_2$的导带（n型掺杂）中的关联电子态，扭转角范围约为$\sim2.3^\circ$至$\sim3.5^\circ$，温度低至mK量级。我们观察到随扭转角变化的重构关联相图——在小扭转角下，关联能隙持续到接近160 K的温度，但在中间角度，能隙仅崩溃至约$\sim20$ K，此时出现了更丰富的相互作用驱动态。在最大扭转角约$\sim 3.5^\circ$时，每个莫尔晶胞1个电子处的关联电阻随加热而增强，这与热辅助局域化或Pomeranchuk-like行为一致。然而，其磁场响应高度各向异性，与石墨烯体系中典型的同位旋莫尔Pomeranchuk效应显著不同。引人注目的是，尽管其电阻性质较弱，这种特征在每莫尔2个电子填充附近甚至在100 K以上仍能持续。我们的结果确立了扭转MoS$_2$作为研究半导体莫尔体系导带中电荷局域化复杂性、内部味自由度和能带拓扑的平台。
英文摘要
Twisted transition-metal dichalcogenides (TMDs) have manifested a rich variety of emerging physical phenomena, yet experimental studies have so far been largely limited in their valence bands (p-doped). Here, we show correlated electronic states in the conduction bands (n-doped) of near-AA-twisted bilayer MoS$_2$ with twist angles ranging from $\sim2.3^\circ$ to $\sim3.5^\circ$, down to the mK temperature regime. A strongly reconstructed correlated phase diagram as a function of twist-angle has been observed - correlated gaps persist to temperatures approaching $160$ K at small twist angles, but collapse to only $\sim20$ K at intermediate angles, where a richer landscape of interaction-driven states emerges. At the largest twist-angle $\sim 3.5\,^{\circ}$, correlated resistance at 1 electron per moiré unit cell is enhanced upon heating, consistent with thermally assisted localization, or, a Pomeranchuk-like behaviour. Its magnetic-field response, however, is highly anisotropic, which differs markedly from that of canonical isospin moiré Pomeranchuk effect in graphene systems. Strikingly, such signature can persist even above 100 K around a filling of 2 electrons per moiré, despite of its weak resistive nature. Our results establish the twisted MoS$_2$ as a platform for studying the complexity of charge localization, internal flavour degrees of freedom, and band topology in conduction bands of semiconducting moiré systems.
Comments14 pages, 8 figures
