Abstract:
The spectra of persistent photoconductivity for InAs/AlSb heterostructures with double quantum wells and a separation AlSb barrier with varying thickness between 0.6–1.8 nm are measured at $T$ = 4.2 K. The electron concentrations in the wells at various illumination wavelengths are determined from the Fourier analysis of Shubnikov-de Haas oscillations. The features associated with the tunneling transparency of a separation barrier 0.6 nm thick (two monolayers) are revealed. The performed self-consistent calculations of the energy profile of a double quantum well showed that a symmetric profile is established in the structures in the region of negative residual photoconductivity, while the region of positive persistent photoconductivity has an asymmetric potential profile, which leads to Rashba spin splitting ($>$ 2 meV at the Fermi level). It is shown that the introduction of the tunneling-transparent separation barrier increases the Rashba splitting.
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