Resonant tunneling in a resistive wire

Abstract

Using a recently developed superposition method, we consider resonant tunneling through a doublebarrier structure in a resistive wire. The wire with finite mean free path permits phase-randomizing scattering; the barriers are described by elastic scatterers. We analyze in detail the evolving residualresistivity dipole surrounding the barriers. We investigate the additional resistance due to the barriers and study the transition from completely coherent to completely incoherent transmission. The transport regime is governed by the ratio of the mean free path to the well width. We discuss the effect of phasebreaking scattering on the tunneling process leading to a decrease in the resonant transmission probability and a rise in the off-resonant one. A formula for the density of states in the well is also obtained.

Unified approach to electron transport in double-barrier structures

“…The condition given by (19) is exactly equal to (1) which has been obtained in Ref. 12, therefore the equivalence of the two approaches has been demonstrated.…”

“…Moreover, the density of states in the well given by (19) simply becomes ρ w ≈ (πhν w T 1 ) −1 (1− R l db ), and from (17) and (18) we readily verify that ballistic electron concentrations n l w and n r w in the well are almost zero. As can be seen from (26) and (27), the double barrier traversal becomes essentially a two-step process, and any effect of quantum interference is implicitly included in R r db and R l db .…”

“…As long as (17)(18)(19) hold true, the two models can be thought as completely equivalent. It is straightforward to see that conditions (17) and (18) are satisfied: in fact, given ρ l ν l = 1/πh, we can re-write (17) as…”

“…Correlation between currents through barriers 1 and 2 is only due to the current conservation in the well, i.e., to the position of the quasi-Fermi level in the well. The density of states in the well, as can be seen from (19), becomes ρ w ≈ (πhν w ) −1 , i.e., any size effect disappears, and ρ w is equal to the density of states in the bulk of the material given by (7). The sequential tunneling approach suits easily this regime, by simply putting F w = F w0 and ρ w ν w = (πh) −1 in (9) and (10).…”

Low-temperature diffusion thermopower inGaN∕AlGaNheterojunctions: Effect of dislocations

“…At an interface, although surface acoustic phonons can as well be excited, in the present work bulk phonons are assumed to provide a qualitatively correct description of the electronphonon interaction. 36 The influence of surface/confined acoustic phonons on thermopower in general, in 2DEG systems is being pursued. Experimental studies of TEP will test the predictions presented in this work.…”