Space-charge buildup and bistability in resonant-tunneling double-barrier structures

Abstract

Using the sequential theory of resonant tunneling, the dc current-voltage characteristic of a double-barrier structure is calculated, taking into account the effect of space charge in the quantum well. A region of current bistability is found over a voltage range which is determined by the maximum space charge and the capacitance of the structure. These parameters are directly related to the periodicity of magnetoquantum oscillations in the current.

Correlation effects in bistability at the nanoscale: Steady state and beyond

“…In their seminal paper Goldman et al 1 reported the observation of bistability in the I-V curve of double-barrier resonant tunneling (DBRT) structures, thus stimulating many theoretical [2][3][4][5] and experimental investigations 6,7 on the subject. The bistability is a nonlinear effect induced by the electrostatic charge buildup in the quantum well and occurs in the bias window of negative differential resistance.…”

“…The bistability is a nonlinear effect induced by the electrostatic charge buildup in the quantum well and occurs in the bias window of negative differential resistance. 1 From the theoretical point of view, various techniques have been used to capture this phenomenon, ranging from a crude estimate of the charge buildup 6 to self-consistent calculations at a mean-field level. [2][3][4][8][9][10] With the increasing interest in transport through nanoscale devices, in particular using molecules as a possible component of future electronic circuits, the study of intrinsic bistability in nanoelectronics has gained new attention.…”

Resonant tunneling and intrinsic bistability in twisted graphene structures

“…(1), can be as large as δV ∼ 100-500 mV (see discussion below). In QW systems, instead, the bias range where bistability occurs is mainly controlled by the amount of charge n QW that can be stored in a quantum well, δV ≈ en QW /C, where C is the interlayer capacitance [14]. Typical carrier densities in the "charged" and "uncharged" states of a bistable QW system, assessed by magnetic oscillation measurements [15], are on the order of n QW ∼ 10 11 /cm 2 and n QW ∼ 0, respectively.…”

Intrinsic Curie temperature bistability in ferromagnetic semiconductor resonant tunneling diodes

“…This effect was first observed by Goldman, Tsui and Cunningham 1 and explained on the basis of charge accumulation in the well region. 2,3,4 Recently, a combination of analytical theory and numerical simulations were used to predict that a RTD with a dilute magnetic semiconductor (DMS) well will undergo a switching of its ferromagnetic critical temperature T C with applied bias voltage V. 5 In this communication, we show that this structure should also exhibit a hysteresis in its T C -V characteristic. To illustrate this effect we present the results of self-consistent simulations of ballistic quantum transport in the effective mass approximation with Coulomb interactions accounted for in the Hartree approximation, combined with linearized mean field equations for DMS ferromagnetism.…”

“…We see a hysteresis in the I-V as expected. 1,2,3,4 Fig. 2 illustrates the origin of the bistability by considering the two stable solutions for the 280mV bias point.…”