Ultra sensitive and vectorial force field imaging at the Quantum/Classical interface – QCForce

This project aims at bringing the outstanding force sensitivity of nano-mechanical oscillators to the wide community of atomic force microscopy users. Our goal is to develop and exploit for both fundamental and applied science objectives a novel kind of force sensors enabling ultra-sensitive vectorial force field imaging based on singly clamped nanowires, enabling six orders of magnitudes improvement over standard atomic force microscopes (AFM) sensitivities.

The first task of the project will consist in developing a vectorial force field sensor prototype based on Silicon Carbide (SiC) nanowires whose vibrations are readout by optical means. Several novel readout schemes based on advanced signal processing of the vibration of the nanowire in 2D will be developed to increase both the measurement speed and its precision. The powerful opto-mechanical readout techniques mandatory to analyse the nanowire dynamics in 2D will be brought into an integrated and reliable setup. This first task will also aim at developing an integrated prototype that could disseminate all across the laboratories interested in scientific imaging and scanning probe techniques at the nanoscale.

The second task will be dedicated to grant a magnetic field sensing functionality to the nanowire and to design the next generation of vectorial magnetic force microscope (MFM) with sensitivities many orders of magnitude larger than existing apparatus. To do so, the nanowire will be functionalised by depositing a nano-magnet on its vibrating extremity. The extreme sensitivity of the nanowire will permit to reduce the probe stray field and thus its impact on the magnetic samples. This will permit in particular to investigate single layers magnetic structures. This apparatus will be applied to study emergent physics in fundamental nano-magnetism, and in particular for investigating room temperature magnetic Skyrmions.

The last task will be dedicated to test the ultimate sensitivity of the nanowire by inspecting its coupling to a single spin qubit. In particular the mechanical backaction of a single Nitrogen-Vacancy spin will be the central part of this task, with the objective of realizing a quantum non demolishing mechanical measurement of the spin state.

The proposed project represents a novel approach to integrated and functionalised nano-sensors, with strong impact in term of dissemination potential and scientific outcomes. The project will be led by Benjamin Pigeau and conducted at Institut Néel in Grenoble, where all the infrastructures and competences required to its success are met.