标题： 通过贝尔贴测温法和石墨烯中的纳米尺度热成像揭示电子-晶格解耦 显示英文标题

标题： Revealing electron-lattice decoupling by Peltier thermometry and nanoscale thermal imaging in graphene

摘要： 低维量子材料中的电流可以使电子远离平衡，造成电子和晶格温度之间的显著不平衡。 然而，目前尚无现有方法能够在低温条件下同时对两种温度进行纳米尺度的测绘。 在此，我们介绍了一种扫描探针技术，该技术可以成像局部晶格温度，并在石墨烯的门控定义的p-n结中提取电子温度。 通过施加交流电流并分析一阶和二阶谐波响应，我们区分了焦耳加热与珀尔帖效应——后者编码了局部电子温度。 这使得首次在石墨烯中对这两种现象进行空间分辨的低温成像成为可能。 即使在适度的电流偏置下，电子温度的增加幅度也比晶格温度高近三个数量级，揭示了强电子-声子解耦，并表明存在一种此前未被认识的电子冷却途径。 我们的最小侵入性方法广泛适用于范德华异质结构，并为研究关联和流体动力学电子系统中的能量耗散和非平衡输运开辟了新途径。 显示英文摘要

摘要： Electrical currents in low-dimensional quantum materials can drive electrons far from equilibrium, creating stark imbalance between electron and lattice temperatures. Yet, no existing methods enable simultaneous nanoscale mapping of both temperatures at cryogenic conditions. Here, we introduce a scanning probe technique that images the local lattice temperature and extracts electron temperature at gate-defined p-n junctions in graphene. By applying an alternating electrical current and analyzing first- and second-harmonic responses, we disentangle Joule heating from the Peltier effect-the latter encoding the local electron temperature. This enables the first spatially resolved cryogenic imaging of both phenomena in graphene. Even under modest current bias, the electron temperature increases by nearly three orders of magnitude more than the lattice temperature, revealing strong electron-phonon decoupling and indicating a previously unrecognized electron cooling pathway. Our minimally invasive method is broadly applicable to van der Waals heterostructures and opens new avenues for probing energy dissipation and non-equilibrium transport in correlated and hydrodynamic electron systems.