Development of a bipolar 50 V output digital-to-analog converter system for ion-shuttling operations

Abstract: The quantum charge-coupled device (QCCD) is one of the notable architectures to achieve large-scale trapped-ion quantum computers. To realize QCCD architecture, ions must be transported quickly while minimizing motional excitation. High-voltage sources are necessary to achieve such high-quality ion transport through a high secular frequency. In this study, we report the development of a field programmable gate array (FPGA)-based digital-to-analog converter (DAC) system with an output voltage range of +/-50 V and demonstrate its effectiveness in ion transport operations. The device provides 16-channel analog output, maximum update rate of 16 mega updates per second (MUPS), slew rate of 20 V/us, and bandwidth of > 200 kHz. By optimizing the voltage sets with quadratic programming, we experimentally confirmed that this DAC system can achieve more than twice the secular frequency attainable when its output range is restricted to +/-10 V, which is consistent with the fact that scaling all electrode voltages by a factor of 5 will scale the secular frequency by the square root of 5. Since the output range of many commercially available DACs is commonly limited to +/-10 V, this increase is effective for ion shuttling operations, such as transport, split and merge. The developed DAC system has potential to increase the speed of ion transport thereby reducing processing times in QCCD-based quantum computers.