Towards microwave optomechanics using a superconducting carbon nanotube weak link

Utilizing the ultra-high sensitivity of a superconducting single-walled carbon nanotube (SWCNT) sensor to probe the quantum ground state is a promising experimental approach for investigations of macroscopic quantum phenomena. However, reproducible and reliable fabrication of such devices is still to be shown due to the demands on high temperature stable materials that the SWCNT growth requires and the crucial role the contact resistance plays for inducing superconductivity into the SWCNT. We approach the challenge with suspended, 300nm long SWCNT contacted on MoRe leads. Good transparency of the superconductor-nanotube contacts allows observation of proxomity induced supercurrents of up to 50 nA, tuneable by gate induced charge. Additionally, we have developed a method to pick-up and place individual suspended SWCNT selectively on metal-electrodes. Using such weak links in an optomechanical microwave setting, coupling energies on the order of 100 kHz can be reached between the mechanical resonator and the electrical cavity