2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/136657We study the effects of electron-electron interactions on the energy levels of GaAs quantum wires (QWs) using finite-bias spectroscopy. We probe the energy spectrum at zero magnetic field, and at crossings of opposite-spin-levels in high in-plane magnetic field B. Our results constitute direct evidence that spin-up (higher energy) levels pin to the chemical potential as they populate. We also show that spin-up and spin-down levels abruptly rearrange at the crossing in a manner resembling the magnetic phase transitions predicted to occur at crossings of Landau levels. This rearranging and pinning of subbands provides a phenomenological explanation for the 0.7 structure, a one-dimensional (1D) nanomagnetic state, and its high-B variants.6 pages, 4 figuresMesoscale and Nanoscale PhysicsStrongly Correlated ElectronsEnergy-level pinning and the 0.7 spin state in one dimension: GaAs quantum wires studied using finite-bias spectroscopytext