Reducing TLS loss in tantalum CPW resonators using titanium sacrificial layers
Researchers used an ultrathin titanium layer to reduce two-level system (TLS) losses at the metal-air interface in tantalum resonators. This method chemically modifies the native oxide by acting as an oxygen getter and a kinetic barrier, resulting in a four-fold increase in internal quality factors. The findings offer a scalable way to improve coherence times without changing the qubit design.