Quantum Foundry Seminar Series: Takashi Taniguchi and Kenji Watanabe

"Spin Phonon Coupling in Diamond Optomechanical Crystals with Embedded Defect Centers"

Abstract: 

Optomechanical crystals have been used to demonstrate a variety of interesting quantum effects, including optomechanical cooling of a nanomechanical resonator to its ground state, optomechanically induced transparency,  squeezed light generation, and quantum state transfer between superconducting qubit quantum information processors and optical quantum communication channels. In comparison to the typical host material of silicon, diamond has several highly desirable properties including a high Young’s modulus, a large band gap that facilitates optical addressing of defect center states, and simpler surface chemistry which reduces the rate at which light involved in the optomechanical interaction is lost via absorption by surface states of the material.  Preliminary investigations of our diamond optomechanical crystals indicate that significant surface optical absorption remains absent from our system despite intracavity photon numbers close to 104, which would create significant loss for a similar system in silicon. This opens up avenues towards both new experiments in optomechanics such as telecom-wavelength optomechanically generated squeezing of mechanical motion, while the easy integration of defect centers that couple to the mechanical degree of freedom permits provides a promising route towards elusive strong coupling between spins and phonons and associated schemes such as optomechanically assisted readout of long-lived spin states.