Millisecond phonon lifetimes in piezoelectric nanomechanical resonators
Researchers fabricated lithium niobate resonators and found that fabrication damage, not material loss, limits phonon lifetimes. By introducing a shadow-mask metallization process to clean surfaces before metal deposition, they achieved intrinsic quality factors comparable to other materials. This breakthrough breaks the traditional tradeoff between coupling and lifetime, leading to significantly higher performance metrics.