Chemical Vapor Deposition of Silicon Vacancy Ensembles in Low Strain Diamond with a NIRIM Type Reactor

In recent decades, improved technology and information theory have brought us closer to a second quantum revolution that utilizes quantum mechanics to its full potential [1]. Diamond is a great platform for optically active defects for quantum information processing, able to host hundreds of different color centers within its wide bandgap. It is transparent from infrared to ultraviolet wavelengths and growth with ¹²C-enriched methane allows for nuclear spin-free material, suppressing spin-spin interactions to improve coherence times. The silicon vacancy (SiV) color center in diamond has particularly favorable properties for broadband quantum memories based on off-resonant Raman transitions. The SiV features inversion symmetry and large ground state splitting (50GHz) making it immune to first-order Stark shifts and large memory bandwidths [2]. The storage time of a quantum memory in a dense SiV ensemble is determined by its inhomogeneous broadening [3] which is heavily influenced by the strain in the material, and therefore growth of high-quality material with high optical density is needed.<br/>Growth of this material will be made possible through a NIRIM-type chemical vapor deposition (CVD) reactor. The reactor is based on a space constrained design [4] and modified for higher vacuum to ensure an extremely low leak rate to achieve very high sample purity. The reduced volume the thin cylindrical quartz tube used in this chamber compared to bell-jar style reactors, and the laminar flow design over the sample surface allows for precise control over gas concentrations and improved purity leading to improved sample quality required for quantum memory applications. In this poster, I will introduce the properties of the SiV and the potential of in-situ silicon doping during CVD.<br/><br/><b>References</b><br/><b>[1]</b> J.P. Dowling and G.J. Milburn, <i>Philos. Trans. R. Soc. </i><i>A </i><b>361, </b>1655 (2003)<b>, </b> <b>[2] </b>J. N. Becker, Ph.D. Thesis, Saarland University (2017), <b>[3] </b>C.<b> </b>Weinzetl, <i>et al.,</i> <i>Phys. </i><i>Rev. Lett.</i> <b>122</b>, 063601<b> </b>(2019), <b>[4] </b>E.H. Thomas <i>et al.,</i> <i>AIP Adv.</i> <b>8</b>, 035325<b> </b>(2018)