Vv. Kuznetsov et al., SHOT-NOISE ENHANCEMENT IN RESONANT-TUNNELING STRUCTURES IN A MAGNETIC-FIELD, Physical review. B, Condensed matter, 58(16), 1998, pp. 10159-10162
We have observed that the shot noise of the tunnel current, I, in a Ga
Sb-AlSb-InAs-AlSb-GaSb double-barrier structure under a magnetic field
can exceed 2qI. The measurements were done at T=4 K in fields up to 5
T parallel to the current. The noise enhancement occurred at each of
the several negative-differential conductance regions induced by the t
unneling of holes through Landau levels in the InAs quantum well. The
amount of the enhancement increased with the strength of the negative
conductance and reached values up to 8qI. These results are explained
qualitatively by fluctuations of the density of states in the well, bu
t point out the need for a detailed theory of shot noise enhancement i
n resonant-tunneling devices. [S0163-1829(98)52540-4].