Observation of the quantum Hall effect in cleaved InAs surfaces

Quantum Hall effect at cleaved InSb surfaces and low-temperature annealing effect

“…The observed results indicate the reduction of the energy of valence electron of donors with increasing Θ. It can be explained by overlapping of the wave functions of neighboring adsorbates.The transport mobility µ t obtained from the zero-field conductivity σ 0 (µ t = σ 0 /eN s ) is one order of magnitude higher than that measured for InAs surfaces [3,4]. This may be attributed to lower acceptor concentration of the substrate as well as to smaller electron effective mass [23].…”

“…Recently, Tsuji et al performed in-plane magnetotransport measurements on 2DESs induced by deposition of Ag atoms at in situ cleaved surfaces of p-type InAs and observed the QH effect for i = 4 [3,4]. However, a high magnetic field above 10 T was required for the observation of the QH effect.…”

“…The transport mobility µ t obtained from the zero-field conductivity σ 0 (µ t = σ 0 /eN s ) is one order of magnitude higher than that measured for InAs surfaces [3,4]. This may be attributed to lower acceptor concentration of the substrate as well as to smaller electron effective mass [23].…”

“…A two-dimensional electron system (2DES) at low temperatures and in a strong magnetic field shows the quantum Hall (QH) effect, in which the diagonal resistivity ρ xx vanishes and the Hall resistance is quantized as R H = h/ie 2 for an integer i [1,2]. Recently, Tsuji et al performed in-plane magnetotransport measurements on 2DESs induced by deposition of Ag atoms at in situ cleaved surfaces of p-type InAs and observed the QH effect for i = 4 [3,4]. However, a high magnetic field above 10 T was required for the observation of the QH effect.…”

“…In the case of p-type crystals, the surface electrons are separated from the three-dimensional carriers in the substrate by the depletion layer. Sample preparation and experimental setup are similar to those used in the previous work on InAs surfaces [3,4]. Sample cleaving was done at low temperatures in an ultra-high vacuum chamber with a 4 He cryostat.…”