Observation of resonant tunneling through GaAs quantum well states confined by AlAs X-point barriers

Abstract
Experimental evidence of resonant tunneling via quasistationary states confined by AlAs X‐point potential energy barriers is reported in GaAs/AlAs double barrier heterostructures grown in the [100] direction. The quantum well energy levels giving rise to the negative differential resistances observed in the current‐voltage characteristics are identified by calculating the energy‐band diagrams of the structures. These resonant energy levels correspond to states confined in the GaAs well not only by the AlAs Γ‐point potential energy barriers but also by the AlAs X‐point barriers. The quasibound X states are associated with the large longitudinal effective mass in AlAs corresponding to the direction perpendicular to the heterojunction interfaces.