JARA-FIT and 2nd Institute of Physics, RWTH Aachen University , 52074 Aachen, Germany.
School of Physics and Astronomy and Manchester Centre for Mesoscience and Nanotechnology, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
Nano Lett. 2017 Oct 11;17(10):5950-5955. doi: 10.1021/acs.nanolett.7b01845. Epub 2017 Oct 3.
Ultralight mechanical resonators based on low-dimensional materials are well suited as exceptional transducers of minuscule forces or mass changes. However, the low dimensionality also provides a challenge to minimize resistive losses and heating. Here, we report on a novel approach that aims to combine different two-dimensional (2D) materials to tackle this challenge. We fabricated a heterostructure mechanical resonator consisting of few layers of niobium diselenide (NbSe) encapsulated by two graphene sheets. The hybrid membrane shows high quality factors up to 245,000 at low temperatures, comparable to the best few-layer graphene mechanical resonators. In contrast to few-layer graphene resonators, the device shows reduced electrical losses attributed to the lower resistivity of the NbSe layer. The peculiar low-temperature dependence of the intrinsic quality factor points to dissipation over two-level systems which in turn relax over the electronic system. Our high sensitivity readout is enabled by coupling the membrane to a superconducting cavity which allows for the integration of the hybrid mechanical resonator as a sensitive and low loss transducer in future quantum circuits.
基于低维材料的超轻机械谐振器非常适合作为微小力或质量变化的特殊换能器。然而，低维性也对最小化电阻损耗和加热提出了挑战。在这里，我们报告了一种新的方法，旨在结合不同的二维（2D）材料来解决这一挑战。我们制造了一种由几层二硒化铌（NbSe）夹在两层石墨烯片之间的杂化膜机械谐振器。该混合膜在低温下表现出高达 245000 的高品质因数，可与最佳的少层石墨烯机械谐振器相媲美。与少层石墨烯谐振器相比，该器件的电阻损耗降低，这归因于 NbSe 层的电阻率较低。固有品质因数的特殊低温依赖性表明，耗散源于双能级系统，而双能级系统通过电子系统弛豫。我们通过将膜耦合到超导腔来实现高灵敏度读出，这允许将混合机械谐振器集成到未来的量子电路中作为灵敏且低损耗的换能器。
