Frequency division multiplexed logic circuits in a GaAs/AlGaAs-based phonon waveguide

An electromechanical phonon waveguide (WG) consisting of a GaAs/AlGaAs heterostructure hosts broad phonon bands that allows piezoelectrically-excited phonon vibrations to be guided. Also, strong excitation of phonons in this device can induce elastic nonlinearities resulting in the frequency conversion of phonons via four wave mixing. Using this functionality we demonstrate frequency-division-multiplexed logic circuits at room temperature, in which AND, OR and XOR gates can be implemented in parallel. Moreover, the broadband response in this device enables the gates to be operated with the speed of up to 3 kbps. Thus, the GaAs/AlGaAs phonon WG offers a promising platform for signal processing devices using phononic degrees of freedom.