Spin dependent polarization response in HgCdTe hot-electron bolometers

Abstract

The paper reports the detection of strong polarization-dependent photo-responses in direct narrow-gap (Eg = 0.084 eV at T = 80 K) HgCdTe thin-layer biased and unbiased hot-electron bolometers (HEBs) with receiving antennas under elliptically polarized THz radiation. The observed effects are assumed to be due to the Rashba spin splitting in HgCdTe, caused by large spin-orbit interactions. The studied detectors demonstrate free-carrier polarization-dependent sensitivity to laser radiation with h 0.0044 eV (ν = 1.07 THz) and 0.0025 eV (ν = 0.6 THz), i.e., with photon energies much less than the band-gap (hν << Eg) at T = 80 and 300 K. The polarization-dependent photocurrent in HgCdTe HEBs with and without applied external constant electric field is shown to have angular dependence of photocurrent with directional reversal on switching the photon helicity.