Acoustic waves at microwave frequencies are widely used in wireless communication and are potential information carriers in quantum applications. However, most acoustic devices are passive components, and the development of phononic integrated circuits is limited by the inability to control acoustic waves in a low-loss, scalable manner. Here we report the electrical control of gigahertz travelling acoustic waves at room temperature and millikelvin temperatures. We achieve phase modulation by tuning the elasticity of a lithium niobate acoustic waveguide via the electro-acoustic effect. This phase modulator is then used to build an acoustic frequency shifter based on serrodyne phase modulation, and phase modulators in a Mach–Zehnder interferometer configuration are used to create an electro-acoustic amplitude modulator. By tailoring the phase matching between acoustic and quasi-travelling electric fields, we achieve reconfigurable non-reciprocal modulation with a non-reciprocity of over 40 dB. To illustrate the potential of the approach in quantum applications, we show that our electro-acoustic modulator can provide coherent modulation of single-phonon-level acoustic waves at 50 mK.

微波频率的声波广泛用于无线通信，是量子应用中潜在的信息载体。然而，大多数声学器件都是无源元件，声子集成电路的发展受限于无法以低损耗、可扩展的方式控制声波。在这里，我们报告了室温和毫开尔文温度下千兆赫行波声波的电气控制。我们通过电声效应调整铌酸锂声波导的弹性来实现相位调制。然后，该相位调制器用于构建基于 serrodyne 相位调制的声频移器，并使用 Mach-Zehnder 干涉仪配置中的相位调制器来创建电声调幅器。通过调整声学和准行进电场之间的相位匹配，我们实现了非互易性超过 40 dB 的可重构非互易调制。为了说明该方法在量子应用中的潜力，我们展示了我们的电声调制器可以提供 50 mK 的单声子级声波的相干调制。