Analytical expression of leakage current through double quantum dots in Pauli spin blockade

We theoretically examine a small current through double quantum dots with Pauli spin blockade, in which electrons cannot be transported without spin–flip or higher-order tunnel processes (cotunneling). Analytical expressions for the current are given in both cases of sequential tunneling and resonant tunneling between the quantum dots and leads. In the former case, the cotunneling weakens the spin blockade and increases a coherent component of the current. When the cotunneling can be disregarded, effective magnetic fields created by nuclear spins (Overhauser fields) can be detected by the observation of the current. In the case of resonant tunneling with Zeeman splitting in an external magnetic field View the MathML source, small Overhauser fields View the MathML source could be detected by the fine tuning of the resonant condition.