Self-synchronization of a NV spin qu-bit on a radio-frequency field enabled by microwave dressing

Abstract

Summary form only given. Probing the quantum world with macroscopic objects has been a core challenge for research during the past decades. Proposed systems to reach this goal include hybrid devices that couple a nanomechanical resonator to a single spin two level system [1]. In particular, the coherent actuation of a macroscopic mechanical oscillator by a single electronic spin would open perspectives in the creation of arbitrary quantum states of motion. In order to anticipate this regime and to explore advanced spin manipulation protocols, we have set up an experiment emulating hybrid spin-mechanical systems of infinite mass by parametrically coupling a radio frequency (RF) field to the spin. A wave-guide allows us to magnetically address the and components of single NV electron spin in nano-diamonds, which represents a tool for investigating the mechanical resonator - spin coupling at ambient conditions. The oscillatory motion of the resonator through a magnetic field gradient is simulated with a magnetic field oscillating at RF frequencies MHz along the axis while the spin population is probed with a microwave field along the direction. We investigate both the steady state regime (with ESR techniques) and the dynamical evolution of the system through Rabi oscillations, which allows investigating the motional sideband generation in the spin energy spectra, revealing how the oscillator motion is imprinted on the spin dynamics, see Fig. 1. Furthermore we demonstrate how the spin dynamics self-synchronizes on the oscillation frequency when the microwave-driven Rabi frequency approaches the oscillation frequency, which is concomitant with an increase in coherence time, as observed in Fig. 2. This mechanism, which appears when the emulated oscillatory motion is driven at large amplitudes, simulating a hybrid spin-mechanical system in the strong coupling regime, can be elegantly described in terms of doubly dressing the spin states. Potential applications for mechanical QND detection of spin states of this phenomenon are discussed.