Rakich, Peter
Date: Friday, September 6, 2019
Time: 10:30
Place: ETH Zurich, Hönggerberg, HPF G 6
Host: Yiwen Chu
Harnessing phonons at the mesoscale: from silicon lasers to hybrid-quantum systems
Peter Rakich
Yale University, USA
In recent years, acoustic phonons have emerged as a powerful resource for signal processing, precision metrology, and quantum information. Phonons are quantum-coherent carriers of information with numerous advantages over their electromagnetic counterparts, including the ability to guide and store signals in much smaller volumes for longer periods of time. The advantages of phonons multiply when the interactions between phonons, photons, and microwave signals can be shaped to create powerful new hybrid technologies. In this talk, we explore methods for controlling and shaping the interactions between photons and acoustic phonons as the basis for both classical and quantum information processing applications. We begin by describing how traveling-wave photon-phonon coupling can be engineered within silicon-based optomechanical waveguides to realize a range of new optomechanical (Brillouin) interactions systems. We harness these interactions to produce new forms mode cooling, non-reciprocal inter-band coupling, integrated signal processing technologies, and new types amplifiers and laser oscillators in silicon photonics.
Beyond silicon, the ability to shape and control such Brillouin interactions within a variety of bulk crystalline media opens the door to new classical and quantum signal processing capabilities. At reduced temperatures, intrinsic sources of phonon dissipation plummet within a variety of crystals, permitting acoustic phonons to live for an astounding number of cycles. By shaping Brillouin interactions to maximize coupling to high Q-factor phonon modes within pristine crystalline substrates, we demonstrate new methods to control of ultra-long-lived phonon modes using light. We show that these bulk acoustic wave techniques open the door to new forms of cryogenic phonon spectroscopy, precision metrology techniques, and high frequency (10-100 GHz) cavity-optomechanical systems with potential for improved robustness against thermal decoherence as the basis for quantum optomechanical signal processing. Beyond cavity-optomechanics, these same phononic resonators also become a building block for new electro-optomechanical and superconducting qubit technologies.
Bio: Rakich
Peter T. Rakich (Ph.D. Physics, MIT) is an Associate Professor of Applied Physics, Physics, and is a member of the Yale Quantum Institute (YQI). He is a recent recipient of the Packard Fellowship for Science and Engineering as well as ONR’s Young Investigator Award for studies of the mechanical properties of light. His research group focuses on topics ranging from nanophotonics and nonlinear optics to cryogenic phonon physics and the quantum properties of sound. He and his team have recently harnessed the mechanical properties of light to create silicon-based Brillouin amplification and Brillouin laser technologies in silicon. His group also works to develop quantum-acoustic memories, ultra-sensitive nonlinear spectroscopy methods, and new types of laser and oscillator technologies. Before he arrived at Yale, he was a Senior Member of the Technical Staff Sandia National Laboratories (2008-2012), where he developed several new programs to harness engineerable nonlinear interactions in nanophotonic systems. He is an author of 47 peer-reviewed journal publications, on topics ranging from photonic crystals to optomechanics, to supercontinuum generation, and cryogenic phonon physics.