No abstract

The study of physical processes associated with acoustic phonons in nitride-based nanosystems is of great importance for the effective operation of modern nanoscale devices. In this paper, a consistent theory of acoustic phonons arising in multilayer nitride-based semiconductor resonant tunneling structures, that can function as a separate cascade of a quantum cascade laser or detector is proposed. Using the physical and geometric parameters of a typical nanostructure, the spectrum of various types of acoustic phonons and the corresponding normalized components of the elastic displacement vector are calculated. It has been established that the spectrum of acoustic phonons of a multilayer nanostructure consists of two groups of the shear phonons dependencies and three groups of dependencies for a mixed spectrum of flexural and dilatational phonons. The dependencies of the acoustic phonons spectrum of the nanostructure and the components of the elastic displacement vector on its geometric parameters are studied. It has been established that for the components of the displacement vector u 2 for shear phonons have a decrease in the absolute values of their maxima with increasing of energy level number. The components u 1 and u 3 of flexural and dilatational phonons behave respectively as symmetric and antisymmetric functions relatively the center of an separate selected layer of the nanostructure. The proposed theory can be further applied to study the interaction of electrons with acoustic phonons in multilayer resonant tunneling structures.

Medical doctors may not have the necessary evidence-based knowledge of specific leadership styles to excel in a leadership role. This article explores the various leadership styles adopted by a clinical professional transitioning into a leadership role. The goal-path theory, developed by Robert House in 1971, was used as the theoretical lens for this study. Twenty peer-reviewed scientific articles, written in English and published between 2015 and 2020, were analyzed and synthesized to produce results. The results showed that employee retention was positively associated with transformational and authentic leadership styles; organizational commitment was positively related to transformational, transactional, and genuine leadership styles; and job satisfaction was positively related to transformational and authentic leadership styles. In particular, the transformational leadership style showed higher employee retention and job satisfaction rates than the transactional and non-interventional leadership styles. The original and transformative leadership styles increased job satisfaction and commitment, but the correlation between an authentic leadership style and these benefits was less clear. Clinical professionals must apply a transformational leadership style to become influential leaders.

In paper, using exact solutions of the stationary Schrödinger equation and the equation of motion for an elastic semiconductor medium, using the secondary quantization formalism, the theory of interaction of electrons with acoustic phonons in a multilayer arsenide-based AlAs/GaAlAs resonant tunneling structure is developed. Using the Matsubara Green's functions and the Dyson equation, expressions, which describe the temperature energy shifts of electronic levels in the nanostructure and their decay rates, are established. Direct calculations of the quantities characterizing the interaction of electrons with acoustic phonons are performed on the basis of physical and geometric parameters of a typical nanostructure, and their dependences on the geometric design of the total potential well of the nanosystem at various temperatures are studied. It is shown that the influence of acoustic phonons leads to the decrease in the quantum electronic transitions frequency in the studied nanostructure, and this effect becomes more noticeable with increasing temperature. It has been established that the absolute values of the electronic stationary states temperature shifts decreases with the increase in the electronic stationary level number. Also, an increase in the temperature entails an increase in the electronic states decay rates that is a dissipation effect directly affecting electronic processes in nanostructures.

No abstract

No abstract