No abstract

No abstract

Nonlocal resistance is studied in a two-dimensional system with a simultaneous presence of electrons and holes in a 20 nm HgTe quantum well. A large nonlocal electric response is found near the charge neutrality point (CNP) in the presence of a perpendicular magnetic field. We attribute the observed nonlocality to the edge state transport via counter propagating chiral modes similar to the quantum spin Hall effect at zero magnetic field and graphene near Landau filling factor ν = 0 .

Ion milling was used to establish the minimum donor doping level N md required for obtaining n-regions with reproducible electron concentration in HgCdTe-based LWIR and MWIR device structures fabricated with ion treatment. The experiments were performed on n-type films grown by molecular beam epitaxy, un-doped and in situ doped with indium with the concentration N In = 5 × 10 14 -10 17 cm −3 . A study of the electrical properties of the milled films showed that N md comprised ∼2 × 10 15 cm −3 for the LWIR and ∼5 × 10 15 cm −3 for the MWIR films. In the films with N In exceeding these critical values, the electron concentration after the milling strictly followed the doping. A need for consideration of the disintegration of the milling-induced defects is also shown.