Negative Differential Conductivity in Semiconductors from First Principles

The negative differential conductivity (NDC) in gas-discharge tubes had been known long before [1] it was discovered in solids [2]. It was the discovery of NDC in semiconductors that invoked renewed interest in this area and opened it to applications in electronics [3]. Recently NDC has been observed in a quantum gas of neutral atoms [4]. It has been observed and predicted in different physical systems, including in normal metals [5], but the underlying physics is very different in each of those systems. In semiconductors it is mainly attributed to the electron transfer between different energy sub-bands. The transport phenomena in general and the NDC in semiconductors in particular is non-linear in
nature and can not be accurately described by linear response theories. We have used time dependent density functional theory to compute the NDC in GaAs, a prototypical semiconductor. It is one of the first materials in which NDC was observed and widely used in NDC
based applications.

[1] R. D. Duncan, Phys. Rev. 17, 302 (1921).
[2] J.B. Gunn, Solid State Commun. 1, 88 (1963).
[3] B. R. Pamplin, Contemp. Phys. 11, 1 (1970).
[4] R. Labouvie et. al., Phys. Rev. Lett. 115, 050601 (2015).
[5] X. Andrade, et. al, Eur. Phys. J. B 91, 229 (2018).