Γ-X intervalley transfer in single AlAs barriers under hydrostatic pressure

Abstract
We have investigated the contribution of Γ‐X intervalley transfer to the tunneling current in single AlAs barrier heterostructures grown on a GaAs substrate by measuring IV characteristics at low temperature and under hydrostatic pressure up to 9 kbar. The application of hydrostatic pressure affects the contribution of the Γ‐X transfer process to the total tunneling current at a given bias voltage. Experimental results are compared with current‐voltage characteristics calculated with a model taking into account the Γ‐X transfer at heterointerfaces. Only transfer processes involving the longitudinal X valley in AlAs are considered in the calculations. Very good agreement is found for low bias conditions at all pressures.