Simulating neutrino oscillations on a superconducting qutrit
Ha C. Nguyen, Bao Gia Bach, Tien Dung Nguyen, Duc Minh Tran, Nguyễn Văn Duy, Hung Q. Nguyen
Abstract
Neutrino oscillations are genuine quantum phenomena in which coherent oscillations are maintained over a long distance. As a result, in principle, the phenomena can be studied efficiently using quantum simulations. In today's noisy quantum hardware, encoding neutrinos in a multiqubit system requires a redundant basis and tricky entangling gates. We encode a three-flavor neutrino in a superconducting qutrit and study its oscillations using Pontecorvo-Maki-Nakagawa-Sakata theory with time evolution expressed in terms of single qutrit gates. The qutrit is engineered from the multilevel structure of IBM transmon devices. High-fidelity gate control and readout are fine-tuned using programming microwave pulses using a high-level language. Our quantum simulations on real hardware match the analytical calculations well in three oscillation cases: vacuum, interaction with matter, and $CP$ violation.