Resonant tunneling of L-valley electrons in GaSb-based double-barrier heterostructures

By means of hydrostatic pressure, the bottom of the conduction band of GaSb can be displaced from the point in the Brillouin zone to the L point. We have used this effect to control the nature of the electrons (or L) available for tunneling at the electrodes of GaSb-AlSb-GaSb-AlSb-GaSb double-barrier heterostructures. In a structure grown along the (100) direction, we have observed negative differential resistance features due to resonant tunneling through two different paths: from the valley in the electrodes through the first quantized state in the well and from the L valley in the electrodes through the first and second L states in the well. In a structure grown along the (111) direction, only resonant tunneling via the path has been observed.