2007/07/31 by Rafael Sánchez, Carlos López-Monís, Gloria Platero
Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.77.165312
published as Phys. Rev. B 77, 165312 (2008) · 7 pages, 6 figures. Extended published version
openalex publication_date 2008/04/07 · arxiv created 2008/04/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We analyze coherent spin rotations in a dc biased double quantum dot driven by crossed dc and ac magnetic fields. In this configuration, spatial delocalization due to interdot tunneling competes with intradot spin rotations induced by the time dependent magnetic field, giving rise to a complicated time dependent behavior of the tunneling current. When the Zeeman splitting has the same value in both dots and spin flip is negligible, the electrons remain in the triplet subspace performing coherent spin rotations and current does not flow. This electronic trapping is removed either by finite spin relaxation or when the Zeeman splitting is different in each quantum dot. In the last case, we will show that by applying a resonant bichromatic magnetic field, the electrons become trapped in a coherent superposition of states and electronic transport is blocked. Then, manipulating ac magnetic fields allows one to drive electrons to perform coherent spin rotations which can be unambiguously detected by direct measurement of the tunneling current.