Simulating wave-wave interactions in plasmas using quantum devices*

We develop a scheme for simulating nonlinear wave-wave interactions in plasmas using quantum computers. We demonstrate the scheme using two qubits on Rigetti's superconducting device. Even with best available qubits, errors need to be mitigated to perform tens of simulation steps. In addition to readout error mitigation, we employ randomized compilation to tailor the error to a well-behaved stochastic channel, whereby each time step uses a different but equivalent gate sequence. Moreover, to account for decoherence, we rescale exponentially decaying probability amplitudes using rates measured from cycle benchmarking. These techniques extend the number of two-qubit operations that the hardware can performed, which enables us to successfully employ algorithms beyond lowest order. Given a limited gate depth, more accurate results may be obtained by either reducing the time step size, which increases the number of steps for a targeted final time, or using higher order algorithms, which require more gates per step. We carefully consider different choices and show tradeoffs can be made to best utilizes limited quantum resources. This study provides a point example of how plasma problems may be solved on near-term quantum computing platforms.