Towards Driving Quantum Systems with the Non-Radiating Near-Field of a Modulated Electron Beam

Abstract

Coherent manipulation of quantum systems generally relies on electromagnetic radiation as produced by lasers or microwave sources. In the experiment presented here we attempt a novel approach to drive quantum systems, as it was recently proposed (D. Rätzel, D. Hartley, O. Schwartz, P. Haslinger, A Quantum Klystron - Controlling Quantum Systems with Modulated Electron Beams. Phys. Rev. Research 3, 023247, 2021). This method utilizes the non-radiating near-field of a modulated electron beam to coherently drive quantum systems, leading to new possibilities for controlling quantum states. For instance, one can locally address subsystems far below the diffraction limit of electromagnetic radiation or paint potentials at atomic scales. In this proof of concept experiment, we want to couple the oscillating near-field of a spatially modulated electron beam to the unpaired spins of a solid, organic radical sample (BDPA) or the hyperfine levels of laser cooled Potassium atoms. The electron beam is generated with a cathodic ray tube from a fast analog oscilloscope.