Phonons in piezoelectric materials have played a pivotal role in radio-frequency signal processing since the advent of the crystal oscillator 100 years ago. Fast-forward to today: we all carry dozens of piezoelectric acoustic wave devices in our pockets, and many promising quantum information processing systems use phonons as a means to mediate interactions between different qubit modalities. However, the phonons in all these examples behave completely linearly. What could we do with phonons if we could enter the regime of strongly nonlinear phononics? In this talk, I will describe a methodology my group has developed to create very strong microwave frequency phononic nonlinearities that now puts us squarely in that regime. I will discuss recent results on phononic phase-preserving amplification, frequency conversion, and phononic Kerr nonlinearity. I will also discuss the prospects of this work looking forward, where these systems may hold the key to an era of quantum phononics with functionality and performance that rivals that of quantum photonics.
Matt Eichenfield is an Associate Professor and the SPIE Endowed Chair in the University of Arizona’s College of Optical Sciences, as well as a Distinguished Faculty Joint Appointee at Sandia National Labs. He received his BS in physics from UNLV in 2004 and his PhD in physics from Caltech in 2010 in the group of Professor Oskar Painter. After finishing his PhD, he was Caltech's first Kavli Nanoscience Prize Postdoctoral Fellow before joining Sandia as a Harry S. Truman Fellow in 2011. At Sandia he founded and led the MEMS-Enabled Quantum Systems group and conducted research there on integrated photonics, phononics, and sensing. He began his joint appointment with UA and Sandia in 2022 and now has research groups at both institutions.