Electron Spin as a Quantum Information Carrier: A Testable Protocol via Single-Electron Double-Slit Encoding

Abstract We propose a testable quantum hypothesisin which electron spin functions as a quantum information carrier. Information is encoded as a controllable phase shift (Φ) in the spin qubit, induced via Larmor precession in a weak magnetic field region. The model predicts a direct relationship between the encoded spin phase and the interference fringe visibility in a modified single-electron double-slit experiment: V = |cos(Φ / 2)| where V represents fringe visibility, and Φ corresponds to the spin-dependent phase difference. A closed-box double-slit configurationis proposed to isolate internal state preparation from external observation while maintaining an externally readable interference pattern. Information readout is achieved using two complementary approaches: 1. Interference visibility analysis 2. Direct spin measurements via a multichannel Mott polarimeter Control experiments include zero-field tests, randomized field configurations, unpolarized sources, and independent verification using two distinct readout modalities. An error budgetaddresses systematic uncertainties such as field leakage, detector asymmetry, and environmental decoherence. If confirmed, these results would demonstrate that electron spin can encode, transport, and reveal quantum information at the single-particle level, shifting the interpretation of the double-slit experiment from an observer-centric narrative toward a physically carried information framework.