Observation of fractional quantum Hall effect in an InAs quantum well

Abstract

The two-dimensional electron system in an InAs quantum well has emerged as a prime candidate for hosting exotic quasi-particles with non-Abelian statistics such as Majorana fermions and parafermions. To attain its full promise, however, the electron system has to be clean enough to exhibit electron-electron interaction phenomena. Here we report the observation of fractional quantum Hall effect in a very low disorder InAs quantum well with a well-width of 24 nm, containing a two-dimensional electron system with a density $n=7.8 \times 10^{11}$ cm$^{-2}$ and low-temperature mobility $1.8 \times 10^6$ cm$^2$/Vs. At a temperature of $\simeq35$ mK and $B\simeq24$ T, we observe a deep minimum in the longitudinal resistance, accompanied by a nearly quantized Hall plateau at Landau level filling factor $\nu=4/3$

Gate-defined quantum point contact in an InAs two-dimensional electron gas

“…We note that compared to GaAs QPCs with similar scattering times [1,2] the quantization of the plateaus is worse and noise is more pronounced, presumably caused by a background disorder potential. Similar conclusions have been drawn from measurements on quantum Hall states in InAs quantum wells [26]. The reason for this remains an open question and will need to be the subject of future investigation.…”

Counterflowing edge current and its equilibration in quantum Hall devices with sharp edge potential: Roles of incompressible strips and contact configuration

“…Theory further predicts that certain fractional QH edge states coupled through a superconductor may harbor even more exotic quasiparticles that would allow for universal topological quantum computation [6][7][8][9][10]. Motivated by these predictions, recently the quality of InAs-based heterostructures has been improved significantly [16,17], which has led to the observation of a fractional QH effect [18].…”

Transport properties of near surface InAs two-dimensional heterostructures

“…InAs is well known to be among a few materials which can interface well with metals and superconductors forming ohmic contacts unlike well known Si and GaAs materials where the interface forms a Schottky barrier. In the past few decades, studies have been focused on high mobility 2DES where the quantum well is placed tens or hundreds of nanometers from the surface [8][9][10][11][12][13][14][15][16] . To make proximity devices in these heterostructures, contacts have to be made after etching the top barriers with in-situ ion cleaning.…”