Integrated Nonlinear Phononic Circuits with Optomechanical Interface – INPhO

The primary objective of INPhO is the design, fabrication and validation of densely integrated nonlinear phononic circuits for parametric information processing at gigahertz frequencies equipped with an optomechanical interface.

To this end, we take advantage of a unique experimental hybrid architecture that combines the high operation frequencies of surface acoustic waves (SAWs) and the nonlinear high-quality factor modes of nanomechanical resonators with one of the arguably most advanced optically active nanosystem, i.e. epitaxial semiconductor quantum dots (QDs).

INPhO will thus see through the development of a set of numerical and experimental tools allowing for (i) a thorough investigation of nonlinear mechanical resonators interfaced by SAWs and (ii) for an optimization of their optomechanical coupling to QDs, in view of designing tunable nonlinear phononic circuit elements combined with an integrated optical read-out.

These nonlinear, on-chip photonic-phononic interconnects integrating programmable elements will be harnessed to push the boundaries of nanomechanical parametric logic to the gigahertz domain. INPhO will build on careful engineering of nonlinear mechanical modal interactions to implement parametric control schemes and demonstrate BIT-flipping, as a first proof-of-concept single-bit logic gate.

The final goal of the project lies in the demonstration of the scalability of the proposed architecture through the design and fabrication of multi-resonator phononic circuits. The devices will encompass coupled and programmable nonlinear phononic elements co-integrated with advanced photonic circuitry for opto-mechanical readout. They will illustrate the perspectives opened by the proposed platform to yield mechanical logic-based devices with radiofrequency-to-optical transduction.

The implementation of these optomechanically-interfaced nonlinear integrated phononic circuits builds upon the unique combination of the complementary expertise of the French and German partners at Besançon and Münster. The WWU partner masters and contributes the heterointegration of QD heterostructures onto SAW substrates. The FEMTO-ST partner has long-standing matching expertise in the design and fabrication of advanced, yet passive phononic devices to localize and guide SAWs on highly coupled piezoelectric materials. The unique bundling of complementary technological know-hows in INPhO allows for an unprecedented combination of both outstanding phononic and optomechanical properties on a unified platform which are out-of-reach in a monolithic approach.

By developing cutting-edge hybrid integrated phononic circuits and devices, INPhO will pave the way towards new paradigms for electronic-photonic-phononic classical information and communication technologies. The INPhO platform, combining nonlinear phononic circuit elements with one of the best solid-state quantum emitter also open far-reaching prospect in the emerging field of hybrid quantum technologies.