Spin and negative differential conductance in the transport through a quantum dot in a magnetic field

Results of combined experimental and theoretical studies of transport spectra of a quantum dot in a magnetic field are reported. In the linear regime, the observed oscillatory behavior of the conductance peaks with varying magnetic field is interpreted in terms of successive rearrangements in the electronic ground state configurations of Fock–Darwin energy levels. Spin-blockade related bimodal behavior is also observed in the peak intensities due to spin dependent tunneling. In the nonlinear regime, a regular pattern of negative differential conductance is detected. This is compared with different theoretical cases demonstrating a subtle interplay between spin dependent tunneling and source and drain resistance asymmetries.