RESUMO
We report the development of an all-optical approach that excites the fundamental compression mode in a diamond Lamb wave resonator with an optical gradient force and detects the induced vibrations via strain coupling to a silicon vacancy center, specifically, via phonon sidebands in the optical excitation spectrum of the silicon vacancy. Sideband optical interferometry has also been used for the detection of in-plane mechanical vibrations, for which conventional optical interferometry is not effective. These experiments demonstrate a gigahertz fundamental compression mode with a Q factor of >107 at temperatures near 7 K, providing a promising platform for reaching the quantum regime of spin mechanics, especially phononic cavity quantum electrodynamics of electron spins.
RESUMO
We report the design, fabrication, and characterization of diamond cantilevers attached to a phononic square lattice. We show that the robust protection of mechanical modes by phononic band gaps leads to a three-orders-of-magnitude increase in mechanical Q-factors, with the Q-factors exceeding 106 at frequencies as high as 100 MHz. Temperature-dependent studies indicate that the Q-factors obtained at a few Kelvin are still limited by the materials loss. The high-Q diamond nanomechanical resonators provide a promising hybrid quantum system for spin-mechanics studies.
RESUMO
We report the development of a composite cavity QED system, in which silicon vacancy centers in a diamond membrane as thin as 100â nm couple to optical whispering gallery modes (WGMs) of a silica microsphere with a diameter of order 50â µm. The membrane induces a linewidth broadening of 3â MHz for equatorial and off-resonant WGMs, while the overall linewidth of the composite system remains below 40â MHz. Photoluminescence experiments in the cavity QED setting demonstrate the efficient coupling of optical emissions from silicon vacancy centers into the WGMs. Additional analysis indicates that the composite system can be used to achieve the good cavity limit in cavity QED, enabling an experimental platform for applications such as state transfer between spins and photons.
RESUMO
We report the fabrication and optical characterization of thin diamond membranes implanted with negatively charged silicon vacancy (SiV-) centers. The variations in the membrane thickness enable the experimental study of optical coherence of SiV- centers as the membrane thickness is varied from 100â nm to 1100â nm. Photoluminescence excitation spectroscopy at low temperature shows that most of the SiV- centers in these membranes feature an optical linewidth ranging between 200 and 300â MHz. Furthermore, there is no discernable dependence of the optical linewidth on the membrane thickness for membranes as thin as 100â nm, indicating the feasibility of incorporating SiV- centers in a varity of diamond nanostructures and still maintaining the excellent optical coherence of these color centers.
RESUMO
We demonstrate the coherent coupling and the resulting transfer of phase information between microwave and optical fields in a single nitrogen vacancy center in diamond. The relative phase of two microwave fields is encoded in a coherent superposition spin state. This phase information is then retrieved with a pair of optical fields. A related process is also used for the transfer of phase information from optical to microwave fields. These studies show the essential role of dark states, including optical pumping into the dark states, in the coherent microwave-optical coupling and open the door to the full quantum state transfer between microwave and optical fields in a solid-state spin ensemble.