Density of impurity states associated with inversion layers

Lima, I. C. da Cunha; Silva, A. Ferreira da; Guimares, P. S.; Perondi, L. F.; Senna, J. R.

doi:10.1103/physrevb.32.2371

Cited by 8 publications

(8 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From these and (23) we see that the shape of the function wE is to be fixed by the correlator of the true potential Wk. This implies that the function wE depends on the features of the disorder interaction in question.…”

Section: Variational Equationsmentioning

confidence: 90%

“…So, the 2D DOS in the deep tail is found to take an asymptotic form somewhat like that proposed by Halperin and Lax [18] for the 3D case, i.e., to be dominated by a decreasing exponential function. The important exponent and the prefactor figuring in (24) are simply ex-pressed in terms of the function Q w , which in turn depends on energy and is given in terms of the potential correlator Wk by (23). This means that equations (23), (24) determine the dependence of the 2D DOS tail on the disorder origin as well as the geometry of the 2D EG.…”

Section: Cumulant Approximation To the 2d Dosmentioning

confidence: 99%

“…The quantum DOS of 2D EGs offered by (23), (24) contains the unknown parameter w, which appears in the theory as the steepness of the non-local harmonic well in the trial action. Therefore, in order to completely determine the function rEY w we need an equation for finding w. To this end, we will derive different variational equations, starting from the requirement that the approximate DOS must be as near to the exact DOS as possible.…”

Section: Variational Equationsmentioning

confidence: 99%

“…In this sense, the present approach is a supplement to our previous semiclassical method [26], which supplies the 2D DOS in the high-energy region (near the subband edge) associated with the long-range potential fluctuations. Thus, we may adopt the following interpolation scheme to obtain the 2D DOS over all energies [15,29,38]: employing the quantum DOS given by (23), (24) and one of (27) to (29) from the lowest energies up to the point at which it crosses the semiclassical DOS given by (19) to (21), and thereafter using the latter.…”

Section: Variational Equationsmentioning

confidence: 99%

See 3 more Smart Citations

Deep Tail in the Density of States of a Disordered Two-Dimensional Electron Gas

Quang¹,

Tung

1998

phys. stat. sol. (b)

View full text Add to dashboard Cite

A theory is given of the density of states (DOS) in the low-energy tail for the disordered twodimensional electron gas (2D EG) in a semiconductor heterostructure subjected to Gaussian random fields of any origin (especially of short range). The calculation is carried out by means of a path-integral technique within the approximation based on a non-local harmonic modelled action and that of the ground-state contribution. A simple analytic expression for the 2D DOS and different variational equations for the curvature of the trial well are then obtained, which describe the DOS tail in explicit dependence on the potential correlator, i.e., on the disorder origin as well as the geometry of the realistic 2D EG. An interpolation scheme for obtaining the 2D DOS over the whole energy region is proposed. The DOS in the deep tail is found to roughly go as a decreasing exponential function whose exponent is proportional to jEj n with n varying from 1 to 2 for very short-and long-range potential correlations, respectively. The case of a Gaussian potential correlator is thoroughly examined.

show abstract

Section: Variational Equationsmentioning

confidence: 90%

Section: Cumulant Approximation To the 2d Dosmentioning

confidence: 99%

Section: Variational Equationsmentioning

confidence: 99%

Section: Variational Equationsmentioning

confidence: 99%

See 2 more Smart Citations

Deep Tail in the Density of States of a Disordered Two-Dimensional Electron Gas

Quang¹,

Tung

1998

phys. stat. sol. (b)

View full text Add to dashboard Cite

show abstract

“…Bound states due to donor impurities do occur in those devices [4]. However, the actual situation is more complicated, involving a finite distance from the inversion layer and effects of screening [5]. Despite the oversimplications, the study of 2-D H 2 molecule formation is also important as a first approach to the problem.…”

mentioning

confidence: 99%

The variational alternant molecular orbital method for 3‐D and 2‐D hydrogen molecule

Silva

Lima

Silva

1986

Int J of Quantum Chemistry

Self Cite

View full text Add to dashboard Cite

The Variational altemant molecular orbital method (VAMO) is described and applied to the case of threedimensional and two-dimensional hydrogen molecules. The energies of the electron system are obtained, together with the equilibrium distances of the molecules. The integrals equivalent to the Slater's integrals of the nonvariational method are described. Applications of this method to realizable systems are described.

show abstract