Photoionization cross sections of hydrogen impurities in spherical quantum dots using the finite-element discrete-variable representation

Abstract

The method of complex-coordinate rotation in a finite-element discrete variable representation is implemented to study the photoionization of hydrogen impurity in spherical quantum dots which are modelled by finite oscillator and Gaussian potentials. The level splitting and crossing of hydrogen impurities due to the variation of dot radii and confining potentials are presented, as well as the shifting down of the energy of hydrogenic impurity toward the combined energy of the free hydrogen and the amplitude of the confining potential. We illustrate the staircaselike behavior in ground and excited energy curves varying with dot radii. The variation of photoionization cross sections with photoelectron energies are given for several dot radii. The cross sections as functions of quantum-dot radii and confining potentials for specific photon energies showing resonancelike profiles are observed and discussed.

Shannon Information Entropy in Position Space for the Ground and Singly Excited States of Helium with Finite Confinements

“…In other related development, spectroscopic atomic structures for confined atomic systems have been under active investigations [25][26][27][28][29][30][31]. In Ref.…”

Photoionization Cross Sections of Atomic Impurities in Spherical Quantum Dots

“…Using this hybrid approach, the kinetic-energy matrix is block diagonal with matrix elements in compact expressions, and the potential-energy matrix elements are given by the potential values at grid points. This method has been implemented to investigate a variety of interesting physical problems, such as quantum-mechanical scattering problems (Rescigno & McCurdy (2000)), bright solitons in Bose-Einstein Condensates and ultracold plasmas (Collins et al (2004)), non-equilibrium Greenąęs function calculations (Balzer et al (2010)), and photoionization of impurities in quantum dots (Lin & Ho (2011)). …”

“…Photoionization cross sections and oscillator strengths of hydrogenic impurities in spherical quantum dots are also obtained for the infinite and finite rectangular well models by Ham and Spector (Ham & Spector (n.d.)), Şahin (Şahin (2008)), and Stevanović (Stevanović (2010)). Recently, Lin and Ho (Lin & Ho (2011)) study the photoionization of hydrogen impurities in spherical quantum dots using the finite oscillator and Gaussian potentials. Chakraborty and Ho (Chakraborty & Ho (2011)) adopt the finite oscillator potential to describe the quantum dot for exploring the autoionization resonance states of helium impurities in quantum dots.…”

“…The confined atomic models are widely used to study a variety of physical systems, such as impurities in quantum dots (Lin & Ho (2011)), atoms encapsulated in fullerenes (Connerade et al (1999); Dolmatov et al (2004)), and atoms under high pressure (de Groot & ten Seldam (1946); Michels et al (1937)). In this article, we focus on the quantum confinement occurring in quantum dots.…”

Ground-State Entanglement Properties of Helium Atom in a Finite Spherical Cavity

“…For example, an attractive version of the potential (2), i.e. V (r ) − A, has been recently used to model a quantum dot [22], to explore the effect of the confinement on the autoionizing resonance states of helium atom [23], and to study a photoionization cross sections of atomic impurities in spherical quantum dots [24]. The main purpose of the present paper is to make a detailed investigation of singlet ground-state entanglement properties of helium atom in the cavity (2).…”