Nanoelectromechanical systems (NEMS) coupled to a single-molecule magnet: Application to study the angular momentum conservation and nano-magnetometry

碳纳米管(CNT)已成为纳米机电系统(NEMS)的重要组成部分。它们的低质量和高杨氏模数产生了高的振荡频率，因此可以用最先进的低温技术实现基态冷却，并在量子区域内实现大的零点运动。此外，在高Q碳纳米管纳米系统中，纳米机械运动和单电子隧穿之间的强耦合允许电子驱动和检测纳米机械运动。因此，CNT NEMS可用于超灵敏的质量传感，或用作单自旋系统的磁性扭矩检测器。根据我们过去几年的经验，我们建议开发具有纳米机械系统的新型杂化分子器件原型，为更快地读出分子自旋态、研究角动量守恒和非经典运动状态开辟新的途径。该项目分为三个任务(T)：任务T1(第一年)是所有其他任务的基础，涉及悬浮碳纳米管(CNT)器件的制造。我们将尝试不同的方法，目的是选择最有效的方法。任务T2(第二年)涉及碳纳米管的纳米机械运动与分子自旋矩的耦合。将测试不同的沉积方法，以找到最合适的一种。然后我们将使用自旋阀效应来检测磁矩的反转，并详细研究角矩守恒(量子爱因斯坦德哈斯效应)。在任务T3(第三年)中，我们打算使用碳纳米管作为扭矩检测器来检测自旋反转。这个项目得到了与化学家团体的大力合作的支持。主要目标是基础科学，但从长远来看，量子电子学的应用是可望的。

Carbon nanotubes (CNT) have become an essential building block for nanoelectromechanical systems (NEMS). Their low mass and high Young's modulus give rise to high oscillation frequencies, therefore enabling ground-state cooling with state-of-the-art cryogenics and a large zero point motion in the quantum regime. Moreover, the strong coupling between nanomechanical motion and single-electron tunnelling in high-Q CNT NEMS allows electronic actuation and detection of the nanomechanical motion. As such, CNT NEMS can be used for ultrasensitive mass sensing or as magnetic torque detectors for single spin systems. Building on our experience of the last years, we propose to develop new prototype hybrid molecular devices with nanomechanical systems opening new avenues to faster readout of molecular spin states, studies of the angular momentum conservation, and non-classical states of motion.The project is divided into 3 tasks (T): Task T1 (1st year) is the basis of all other Ts and concerns the fabrication of suspended carbon nanotube (CNT) devices. We will try different methods with the aim to select the most efficient method. Task T2 (2nd year) concerns the coupling of the nanomechanical motion of a CNT to the molecular spin moment. Different deposition methods will be tested in order to find the most adequate one. We will then use the spin valve effect to detect the reversal of the magnetic moment and study in detail the conservation of the angular moment (quantum Einstein de Haas effect). In Task T3 (3rd year), we intend to use the CNT as a torque detector for spin reversal detection. This project is supported by strong collaborations with chemist groups. The main target concerns fundamental science, but applications in quantum electronics are expected in the long run.