2007/10/16 by Kunal K. Das
Engineering · Physics and Astronomy · #Molecular Junctions and Nanostructures #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices #cond-mat.mes-hall
paper · pdf · doi:10.1088/0953-8984/20/45/455202
published as J. Phys.: Condens. Matter 20 (2008) 455202 (14pp) · 16 pages, 6 figures
arxiv created 2007/10/16 · openalex publication_date 2008/10/13 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We provide provide a detailed study of biasless coherent transport of singlet electron pairs in one-dimensional (1D) channels induced by electron-electron interactions that are time-varying in certain spatially localized regions of the channel. When the time variation is cyclic, the mechanism is analogous to the adiabatic quantum pumping of charge and spin previously studied. However, the presence of interactions that vary only in localized regions of space requires an intrinsically two-body description which is irreducible to the 1D single particle scattering matrix elements that are sufficient to describe quantum pumping of charge and spin. Here we derive a generalized theory for the pumping of such interacting pairs starting from first principles. We show that the standard description of charge pumping is contained within our more broadly applicable expressions. We then apply our general results to a concrete lattice model and obtain an exact analytical expression for the pumped singlet current. We further demonstrate that such a model can be implemented with a chain of currently available quantum dots with certain minor modifications that we suggest; we present a detailed numerical feasibility analysis of the characteristics of such experimentally realizable quantum dots, showing that the requirements for a measurable pumped singlet current are within experimental range.