Study of high quality factor resonators
Understanding dissipation and controlling low dissipation systems enable classical and quantum applications, including force sensing, timekeeping, quantum memory, and transduction. In this dissertation, we study two types of high quality factor resonators, silicon nitride mechanical resonators and a low loss organic-based ferrimagnet vanadium tetracyanoethylene (V[TCNE]x). In the first theme, we study the parametric coupling between two high quality factor mechanical modes in a silicon nitride membrane and demonstrate a dynamic protocol to enhance force sensitivity beyond the thermal noise limit. Building upon the parametrically coupled system, we theoretically study a non-degenerate parametric amplifier/oscillator system with an exponential non-Markovian system-bath interaction. We demonstrate the emergence of a new phase that has no counterpart in equilibrium systems. Such exponential non-Markovian system-bath interactions enable the generation of robust two-mode entanglement at finite temperatures, which has significance for quantum information and metrology. In the second theme, we study the material properties and aging of the high quality factor magnetic material V[TCNE]x with photoluminescence, micro-focused Raman spectroscopy, SQUID magnetometry and ferromagnetic resonance. We find a correlation between optical and magnetic measurements, which enables the local optical assessment of magnetic properties of V[TCNE]x. We demonstrate laser patterning to create magnetic structures, reaching micron scale resolution. Our results demonstrate a new method of patterning V[TCNE]x, with potential applications for in situ patterning, which could compensate for growth-to-growth variations in saturation magnetization and anisotropy.