Far-infared laser spectroscopy of two dimensional holes in strained-layer heterostructure and superlattices.

摘要

We report far-infrared magneto-transmission data at 4.2 K on a series of p-type strained layer Al(sub x)Ga(sub 1 (minus)x)As/In(sub y)Ga(sub 1 (minus)y)As/GaAs quantum well (QW) structure and InAs(sub 0.15)Sb(sub 0.85)/InSb superlattices (SLS). The Al(sub x)Ga(sub 1 (minus)x)As/In(sub y)/Ga(sub 1 (minus)y)As/GaAs QW structure consists of strained In(sub y)Ga(sub 1 (minus)y)As layers of 100 (Angstrom) in thickness and a space layer having thickness (W(sub sp)) ranging from 30 (Angstrom) to 700 (Angstrom). The InAs(sub 0.85)/InSb SLS was grown on top of a 1.0(mu)m InAs(sub 0.15)Sb(sub 0.95) strain relief buffer layer consisting of alternating layers of 100 (Angstrom) InAs(sub 0.15)Sb (sub 0.85) and 200 (Angstrom) InSb. The detail of the sample structures has been described elsewhere. The two-dimensional (2D) hole density (p(sub 2D)) of the sample is obtained from the period of the Shubnikov-de Hass oscillations in quantum transport measurements made at 4.2 K. The magneto-transimission experiments are performed in magnetic field (B) up to 8.5 T using polarized radiation and the spectrum is displayed as 4 Log(sub 10)(T(B)/T(0)), where T(B) is the transmittance at B.