电荷密度波(CDW)是凝聚态物理中的热点研究问题之一，其形成机理源于费米面嵌套、电声耦合或其他尚未探明的因素。最近的研究发现，准二维CDW体系KMo6O17中存在一个非常规的表面CDW态，其转变温度和CDW能隙远远高于体态CDW。该表面CDW态被认为是表面的电子-电子相互作用增强引起的，但是电子-电子相互作用如何增强CDW态依然是一个值得研究的课题。强磁场作为一种有效的电子调控和表征手段，是研究体系电子能带结构和相互作用的强有力手段。在本项目中，我们计划对钼紫青铜AMo6O17和η-Mo4O11家族体系微纳结构进行深入研究。我们将通过强磁场电输运测量，结合门电压调控，研究维度对CDW态的调控作用。通过本项目，我们希望能够揭示体系中可能存在的相互作用，澄清表面CDW态的来源，理解CDW转变的本质;并利用强磁场极端条件，探索量子受限的CDW体系中的新效应。

Charge density wave has been a longstanding research topic in condensed matter physics, whose origins are Fermi surface nesting, strong electron-phonon coupling and other possible interactions which have yet been determined. A recent study revealed the presence of a surface-enhanced CDW state with a much higher CDW transition temperature and larger CDW gap. The surface CDW state is considered due to the enhanced electron-electron interaction when the dimensionality is reduced. However, how the electron-electron interaction enhances the CDW is still under debate and remains unexplored. Magnetic field is one of the most powerful tools to study the electronic band structures and reveal the interactions of a system. In the present project, we propose to investigate the exotic physical properties of molybdenum purple bronzes AMo6O17 and η-Mo4O11 nanostructures systematically. We will study the transport properties under high magnetic fields, together with the gating effect, to research the effect of the dimensionality on the CDW state in purple bronzes. Through this project, we expect to reveal the possible interactions in the system and understand the underlying nature of the CDW transition. Furthermore, we will also explore the new physics and novel quantum states under extremely high magnetic fields in 2D CDW systems.