Superposition principle for qubit states in spin-projection mean representation

TL;DR

This paper formulates a nonlinear superposition rule for qubit states based on mean spin projections, providing explicit expressions and discussing experimental verification possibilities.

Contribution

It introduces a novel nonlinear superposition principle for qubit states using mean spin projections and derives explicit formulas for superposition states.

Findings

Explicit expression for superposition state in terms of initial states

Discussion on experimental verification of the superposition rule

Framework for testing superposition in spin-projection measurements

Abstract

The superposition principle of two qubit states is formulated as nonlinear addition rule of mean spinprojection onto three perpendicular directions. The explicit expression for the mean value determining the superposition state in term of the two initial pure states of the qubit is obtained. Possibility to check the superposition expression in experiments is discussed.