Scalable Software Defined Radio Platform for Precision Control of Nuclear Spin Qubits

Neutral atom quantum computing systems require precise control over the duration, frequency, amplitude, and phase of laser pulses at nanosecond timescales for cooling, trapping, state preparation, and the execution of quantum algorithms. In this talk, we will describe a custom software defined radio (SDR) hardware platform that generates long, repetitive sequences of arbitrary RF waveforms in the 10 MHz-10 GHz range to selectively address individual qubits and actuate sequences of 1- and 2-qubit gates. The control system must perform classical computations such as loops, branches, and subroutine callouts in real time and within the coherence time of the qubits in order to support quantum error correction and other iterative operations. We have implemented a lightweight, highly efficient flow control mechanism for these classical computations by means of Lua scripts that execute on the embedded processor of the SDR and feed CPU-like instructions to the input buffers of the arbitrary waveform generator.