Diamond optomechanical crystals

Abstract

GUIDED ACOUSTIC PHONON MODES IN DIAMOND OPTOMECHANICAL CRYSTALSTo supplement our discussion of the guided acoustic phonon modes supported by diamond optomechanical crystals (OMCs), we present normalized displacement profiles of the nominal unit cell at the Γ (kx = 0) and X (kx = π/a) points of its mechanical bandstructure (originally displayed in Figure 1(c) of the main text). Figures S1 and S2 reveal the guided acoustic modes categorized by even (solid black lines) and odd (dashed blue lines) vector symmetries about the y-axis, respectively, with displacement profiles originating from the indicated band edges shown as insets (three dimensional, top down and cross-section views included). Note, the unit cell lattice constant in the displacement profiles is displayed between the (hx, n, hy, n) and (hx, n+1, hy, n+1) center points, in order to clearly reveal displacement components within the air holes. Mechanical simulations included here and throughout the main text use the full anisotropic elasticity matrix of diamond [1], where (C11, C12, C44) = (1076, 125, 578) GPa. However, due to considerations expanded upon in section 5 of this supplementary material, devices characterized in this work were ultimately fabricated with their x-axis oriented with the in-plane [110] crystallographic direction. Thus, a rotated version of the anisotropic elasticity matrix ensured proper device orientation in our simulations, with guided mode propagation along the x-axis aligned with the [110] crystallographic direction, with the z-axis aligned with [001]. Only a small (< 10 %) change in the guided mode frequencies was observed between simulations with unit cell x-axis alignment to the [100] and [110] in plane crystal directions.While the mechanical bandstructures reveal a rich library of guided acoustic modes in the few to 16 GHz frequency range, only guided modes originating from y-symmetric bands ultimately couple to the optical cavity [2]. Additionally, modes originating from the Γ-point ensure large optomechanical coupling rates in the final design [3]. With this in mind, two modes from the Γ-point of ysymmetric bands enable design of diamond OMCs with large single-photon optomechanical coupling rates, go. Specifically, the Γ-point modes from the 4 th and 7 th y-symmetric bands, referred to as the "flapping" and "swelling" modes, respectively, were both investigated. OPTIMIZED DIAMOND OPTOMECHANICAL CRYSTAL DESIGNAs discussed in the main text, the final diamond OMC design relies on transitioning from a "mirror" region formed by the base unit cell in Figure 1(a) to a "defect" cell, which localizes the target

Fiber-Coupled Diamond Quantum Nanophotonic Interface

“…Together, recent efforts in quantum science and nanoscale engineering of diamond have resulted in the demonstration of a solid-state single-photon switch based on a single silicon-vacancy (SiV) color center embedded in a diamond PCC, as well as observation of entanglement between two SiVs implanted in a single diamond waveguide [12]. As diamond nanophotonics continues to enable advances in other disciplines (including non-linear optics [34,35] and optomechanics [36,37]), the demand for scalable technology necessitates moving beyond isolated devices, to fully integrated on-chip nanophotonic networks in which waveguides route photons between optical cavities [38]. Moreover, for applications involving single photons, such as quantum nonlinear optics with diamond color centers [12,22], efficient off-chip optical coupling schemes are necessary to provide seamless transition of on-chip photons into commercial single mode optical fibers [39][40][41][42].…”

Coherent Atom-Phonon Interaction through Mode Field Coupling in Hybrid Optomechanical Systems

“…(3)], with dissipations introduced through Lindblad operators [19], using cavity decay rate κ=2π ¼ 3 GHz and emitter decay rate Γ=2π ¼ 0.05 GHz (measured for NV centers in photonic crystals [20]). The QE is excited by a short π pulse, followed by a pulse that excitesâ 0 to a maximum population of n cav ¼ 5 × 10 4 , shown to be experimentally feasible in diamond [29]. We note that the emitter is not directly affected by the large optical intensity as the field is zero at its position.…”

“…Cavities are defined by local periodicity variations, which yield colocalized and dispersively coupled optical and mechanical resonances [28,29]. Placing three defect cavities along one nanobeam leads to both optical and mechanical hybridization.…”

Advances in diamond nanofabrication for ultrasensitive devices

“…27). A more remarkable record is achieved in optomechanical single crystal diamond micro disk resonators operating in ambient condition 12,33 , with f c · Q m = 19 THz, while similarly f c · Q m = 9.5 THz at room temperature in polycrystalline 3C-SiC optomechanical micro-resonators has been achieved (the theoretical maximum achievable in SiC being f c · Q m = 300 THz at room temperature) 34 . It is expected that a similar race could start regarding MEMS/NEMS 35 in reconsidering conventional materials, hosting color centers as diamond, such as SiC, for applications envisaged for current diamond nanomechanical resonators.…”

“…In analogy with optical PHC, diamond crystals (OMCs) have been proposed, where a quasi-periodic diamond nanostructure leads to coupling of an optical cavity field to a mechanical mode via the radiation pressure of light. In contrast to other material systems, diamond OMCs operating in the resolved sideband regime possess large intra cavity photon capacity ( 410 5 ) and a sufficient opto-mechanical coupling rate to exceed a cooperativity of~1 at room temperature 12,32,33 . In the above examples, the NV spin ground state is coupled with mechanical modes and read out optically, whereas other methods are employed when the NV excited state is coupled to the cavity mechanical modes.…”