Collective Neutrino Oscillations on a Quantum Computer

TL;DR

This paper demonstrates the calculation of neutrino energy levels and oscillations using quantum algorithms on IBM Q hardware, showing feasibility and accuracy in simulating complex many-body neutrino systems.

Contribution

It introduces a quantum computing approach to simulate collective neutrino oscillations, including Hamiltonian simplification and Trotterization techniques for efficient implementation.

Findings

Energy eigenvalues computed with good accuracy

Transition probabilities match exact results

Hamiltonian block separation reduces noise

Abstract

We calculate the energy levels of a system of neutrinos undergoing collective oscillations as functions of an effective coupling strength and radial distance from the neutrino source using the quantum Lanczos (QLanczos) algorithm implemented on IBM Q quantum computer hardware. Our calculations are based on the many-body neutrino interaction Hamiltonian introduced in Ref.\ \cite{Patwardhan2019}. We show that the system Hamiltonian can be separated into smaller blocks, which can be represented using fewer qubits than those needed to represent the entire system as one unit, thus reducing the noise in the implementation on quantum hardware. We also calculate transition probabilities of collective neutrino oscillations using a Trotterization method which is simplified before subsequent implementation on hardware. These calculations demonstrate that energy eigenvalues of a collective neutrino system and collective neutrino oscillations can both be computed on quantum hardware with certain simplification to within good agreement with exact results.