Influence of magnetic field on 1/f noise in GaAs resistors without surface effects

Abstract

The influence on magnetic field on l/fnoise in a planar GaAs resistor grown by molecularbeam epitaxy and without surface effects was investigated experimentally. The experimental results can be explained by the number fluctuation model but not by the mobility fluctuation modeL Previously, experimental results indicating number fluctuation type of l/fnoise were mostly attributed to the surface effects associated with the particular structures used for the experiments. In our device the surface effects were diminished so that the fluctuations of the bulk current could be considered to produce the 1/fnoise.

The effect of a transverse magnetic field on 1/f noise in graphene

“…The absolute value of the magnetoresistance is comparable with that observed in Ref. 22 for the samples with l 0 ¼ 1860 cm 2 /Vs at T ¼ 330 K. It is somewhat smaller than the magnetoresistance of SLG with the mobility $6200 cm 2 /Vs at T ¼ 2.9 K. 23 Dashed lines in Figs. 1(a) and 1(b) show the maximum geometrical magnetoresistance calculated as Dq=q 0 ¼ ðl 0 BÞ 2 for l 0 ¼ 500 cm 2 /Vs.…”

“…Non-monotonic dependence and strong increase of noise in high magnetic fields make graphene very different from what is observed in other electronics systems. In particular, GaAs samples 20,[22][23][24] and GaN/AlGaN transistors 25,26 exhibit an absence of or a weak dependence of noise on the magnetic field, consistent with the number of carriers fluctuations as an origin of noise in these materials. The scattering mechanisms and magnetoresistance in graphene are still under discussion.…”

Suppression of $1/f$ noise in graphene due to non-scalar mobility fluctuations induced by impurity motion

“…For Corbino devices with isotropic (scalar) mobility fluctuations δµ 0 , the current fluctuations should vanish at a sweet spot having µ 0 B = 1. In practice, the sweet spot does not reduce the noise down to zero, but non-idealities/other noise sources will limit the reduction [23][24][25][26][27] . On the other hand, partial correlations between mobility fluctuations in radial δµ r and azimuthal δµ ϕ direction may account for the observed noise reduction.…”

“…This feature means that, if there are isotropic mobility fluctuations (fully correlated in two orthogonal directions) causing 1 f noise, this noise component will be suppressed to zero at µ 0 B = 1 22 ; here µ 0 denotes the mobility at B = 0. This behavior has unsuccessfully been searched for both in two-dimensional electron gas [23][24][25][26] as well as in graphene 27 . Our experimental results display a clear suppression of noise as a function of B, with a minimum around µ 0 B ≃ 1.…”

Magnetic‐TEGFET: Transistor Without a Gate

“…This is shown in Figure for the donor‐doped sample in increasing magnetic fields. In the standard behavior, the transverse magneto‐resistance is proportional to B 2 …”