Quantum spin-flavour memory of ultrahigh-energy neutrino

TL;DR

This paper investigates the quantum uncertainties in ultrahigh-energy neutrino measurements, introducing the concept of quantum spin-flavour memory, which reduces uncertainty and is quantified via a generalized Kraus's trade-off relation.

Contribution

It introduces quantum spin-flavour memory as a new concept and applies advanced entropic measures to quantify it in the context of neutrino propagation through magnetic fields.

Findings

Quantum spin-flavour discord quantifies quantum spin-flavour memory.

Quantum memory reduces measurement uncertainty in neutrino states.

Most quantum correlation measures are irrelevant, except quantum discord.

Abstract

There are two types of uncertainties related to the measurements done on a quantum system: statistical and those related to non-commuting observables and incompatible measurements. The latter indicates the quantum system's inherent nature and is in the scope of the present study. We explore uncertainties related to the interstellar ultrahigh-energy neutrino and introduce a novel concept: quantum spin-flavour memory. Advanced uncertainty measures are entropic measures, and the effect of the quantum memory reduces the uncertainty. The problem in question corresponds to a real physical event: high-energy Dirac neutrinos emitted by some distant source and propagating towards the earth. The neutrino has a finite magnetic moment and interacts with both deterministic and stochastic interstellar magnetic fields. To describe the effect of a noisy environment, we exploit the Lindblad master equation for the neutrino density matrix. Quantum spin-flavour memory we quantify in terms of the generalized Kraus's trade-off relation. This trade-off relation converts to the equality when quantum memory is absent. We discovered that while most measures of quantum correlations show their irrelevance, the quantum spin-flavour discord is the quantifier of the quantum spin-flavour memory.