Scaling of Coulomb and exchange-correlation effects with quantum dot size

Pandey, Rakesh Kumar; Harbola, Manoj K.; Singh, Vijay A.

doi:10.1103/physrevb.67.075315

Cited by 12 publications

(10 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For a hydrogenic impurity, Z = 1, m * is the effective mass of the electron inside the QD in units of m e , the free electron mass. We model the external potential as [13,14] V ext (r) =…”

Section: Emt Modelmentioning

confidence: 99%

Defects in semiconductor nanostructures

2008

Self Cite

View full text Add to dashboard Cite

Impurities play a pivotal role in semiconductors. One part in a million of phosphorous in silicon alters the conductivity of the latter by several orders of magnitude. Indeed, the information age is possible only because of the unique role of shallow impurities in semiconductors. Although work in semiconductor nanostructures (SN) has been in progress for the past two decades, the role of impurities in them has been only sketchily studied. We outline theoretical approaches to the electronic structure of shallow impurities in SN and discuss their limitations. We find that shallow levels undergo a SHADES (SHAllow-DEep-Shallow) transition as the SN size is decreased. This occurs because of the combined effect of quantum confinement and reduced dielectric constant in SN. Level splitting is pronounced and this can perhaps be probed by ESR and ENDOR techniques. Finally, we suggest that a perusal of literature on (semiconductor) cluster calculations carried out 30 years ago would be useful.

show abstract

“…For a hydrogenic impurity, Z = 1, m * is the effective mass of the electron inside the QD in units of m e , the free electron mass. We model the external potential as [13,14] V ext (r) =…”

Section: Emt Modelmentioning

confidence: 99%

Defects in semiconductor nanostructures

2008

Self Cite

View full text Add to dashboard Cite

show abstract

“…In order to study the shape dependence of binding energy, we model [16,17] our external potential as follows:…”

Section: Modelmentioning

confidence: 99%

“…We call it the "Hubbard U". 11,12 For a one orbital system the last two terms in the Eq. (5) cancel each other in the HS scheme but they do not cancel within the LDA.…”

mentioning

confidence: 99%

Shallow–deep transitions of neutral and charged donor states in semiconductor quantum dots

2004

Self Cite

View full text Add to dashboard Cite

We carry out a detailed study of neutral ͑D 0 ͒ and charged ͑D − ͒ impurity states of hydrogen-like donors in spherical semiconductor quantum dots. The work is carried out within the effective mass theory, treating many-body effects within the local density approximation and the Harbola-Sahni schemes. We observe that the donor level undergoes shallow to deep transition as the dot radius is reduced. On further reduction of the dot radius it becomes shallow again. This suggests the possibility of carrier "freeze out" for both D 0 and D − . Further, our study of the optical gaps also reveals a nonmonotonic shallow-deep behavior.

show abstract

“…A recent experiment has identified atom‐like electronic states in nanocrystal QDs 27. Some of the commonly studied topics in 3D QDs are the formation of energy shells in their spectra 28, the control of electronic correlations 29, the formation of Wigner molecules in the system 30, and the influence of the Coulomb interaction in their spectra 31, 32. In such spherically defined 3D QD, both spin and orbital angular momenta are good quantum numbers, and the many‐particle eigenstates can be labeled according to the usual LS ‐coupling scheme 33, where the analytic many‐particle eigenstates are given as a sum over appropriate Slater determinants.…”

Section: Introductionmentioning

confidence: 99%

Restricted and unrestricted Hartree–Fock approaches applied to spherical quantum dots in a magnetic field

Destefani¹,

Vianna²,

Marques³

2006

Int J of Quantum Chemistry

View full text Add to dashboard Cite

ABSTRACT:The Roothaan and Pople-Nesbet approaches for real atoms are adapted to quantum dots in the presence of a magnetic field. Single-particle Gaussian basis sets are constructed, for each dot radius, under the condition of maximum overlap with the exact functions. The chemical potential, charging energy, and total spin expected values are calculated, and we have verified the validity of the quantum dot energy shell structure as well as Hund's rule for electronic occupation at zero magnetic field. At finite field, we have observed the violation of Hund's rule and studied the influence of magnetic field on the closed and open energy shell configurations. We have also compared the present results with those obtained within the LS-coupling scheme for low electronic occupation numbers. We focus only on ground-state properties and consider quantum dots populated up to 40 electrons, constructed by GaAs or InSb nanocrystals.

show abstract

Scaling of Coulomb and exchange-correlation effects with quantum dot size

Cited by 12 publications

References 14 publications

Defects in semiconductor nanostructures

Defects in semiconductor nanostructures

Shallow–deep transitions of neutral and charged donor states in semiconductor quantum dots

Restricted and unrestricted Hartree–Fock approaches applied to spherical quantum dots in a magnetic field

Contact Info

Product

Resources

About