Kavli Affiliate: Grace Xing | Summary:Using molecular beam epitaxy, we have realized thin films of titanium nitride (TiN) on c-plane sapphire that exhibit the lowest observed full-width at half maximum X-ray rocking curve width of 18 arcsec. Though the (111) oriented TiN exhibits an abrupt and crystalline interface with sapphire, for the first time we observe sub-surface defects in the sapphire substrate, which nucleate structural defects in the epitaxial TiN layer. Using quarter-wavelength coplanar waveguide (CPW) resonators in a 3 textmu m/6 textmu m/3 textmu m gap/strip/gap lines in a hanger geometry, we find the internal quality factor of the TiN resonators to be $>10^6$ in the single-photon $langle n rangle sim 1$ limit at 5.8 GHz and 10 mK, rising to $>20 times 10^6$ at $langle n rangle sim 10^6$. The results are of high interest for applications of superconducting TiN in several areas, and provide a path towards epitaxial Josephson junctions with crystalline barriers in the future for high coherence qubits. | Search Query: arXiv Query: search_query=au:”Xing Huili Grace”&id_list=&start=0&max_results=10Read More