Tunable and Transferable Diamond Membranes for Integrated Quantum Technologies

Abstract

Color centers in diamond are widely explored as qubits in quantum technologies. However, challenges remain in the effective and efficient integration of these diamond-hosted qubits in device heterostructures. Here, nanoscale-thick uniform diamond membranes are synthesized via “smart-cut” and isotopically ( 12 C) purified overgrowth. These membranes have tunable thicknesses (demonstrated 50 to 250 nm), are deterministically transferable, have bilaterally atomically flat surfaces ( R q ≤ 0.3 nm), and bulk-diamond-like crystallinity. Color centers are synthesized via both implantation and in situ overgrowth incorporation. Within 110-nm-thick membranes, individual germanium-vacancy (GeV – ) centers exhibit stable photoluminescence at 5.4 K and average optical transition line widths as low as 125 MHz. The room temperature spin coherence of individual nitrogen-vacancy (NV – ) centers shows Ramsey spin dephasing times ( T 2 * ) and Hahn echo times ( T 2 ) as long as 150 and 400 μs, respectively. This platform enables the straightforward integration of diamond membranes that host coherent color centers into quantum technologies.

Hybrid Quantum Systems with Artificial Atoms in Solid State

“…These membranes are transferred using stamp transfer printing over trenches defined in a carrier wafer, allowing for suspended structures to be defined in the transferred membranes. [200] SiV centers are introduced at targeted locations through focused ion beam implantation [201,202] or ion beam implantation through masks, [138,203] with lateral accuracy limited to that of electron beam lithography used to define the mask. [138] Single qubit operations can be performed through optical addressing, while multi-qubit operations are mediated via the phonon mode, [204] analogous to trapped ion quantum computing.…”

Dynamic Strain Modulation of a Nanowire Quantum Dot Compatible with a Thin-Film Lithium Niobate Photonic Platform

“…Quantum computation with on-chip photonic qubits has emerged as an important research area in quantum technologies. − In addition to the manipulation and detection of individual photons, achieving deterministic integration of single and indistinguishable photon sources is essential for the scalability and complexity of quantum photonic circuits. − Although more technologically challenging than monolithic approaches, − the heterogeneous integration of high-quality quantum emitters offers the possibility of producing more efficient devices and incorporating additional functionalities that would be difficult to achieve in single material systems. Toward this direction, III/V semiconductor quantum dots (QDs), − and defects in crystals , or in 2D materials − have been successfully transferred to Si, SiN, AlN, or LiNbO 3 while maintaining good performances as single photon sources. In addition to their individual properties, multiple sources integrated on the same chip must be spectrally identical if indistinguishable photons are to be generated for linear quantum operations .…”

“…5−7 Although more technologically challenging than monolithic approaches, 8−10 the heterogeneous integration of high-quality quantum emitters offers the possibility of producing more efficient devices and incorporating additional functionalities that would be difficult to achieve in single material systems. Toward this direction, III/V semiconductor quantum dots (QDs), 11−15 and defects in crystals 16,17 or in 2D materials 18−20 have been successfully transferred to Si, SiN, AlN, or LiNbO 3 while maintaining good performances as single photon sources. In addition to their individual properties, multiple sources integrated on the same chip must be spectrally identical if indistinguishable photons are to be generated for linear quantum operations.…”

Plasmonic Diamond Membranes for Ultrafast Silicon Vacancy Emission

“…Looking ahead, thin film diamond affords versatility as a functional layer for future integrated heterostructure stacks. Recently, fabrication of transferrable diamond films with tunable, uniform thickness down to 50 nm has been demonstrated. , A device that simultaneously hosts layers of superconducting, nonlinear, and/or photonic components could achieve advanced quantum state manipulation and open novel pathways toward a comprehensive device design for quantum information and sensing. Fabrication approaches such as laser annealing could enable deterministic generation of cavity-coupled single photon sources in diamond.…”