Shape-dependent electronic and thermodynamic properties of three-dimensional laterally coupled InAs–GaAs double quantum dots

In this work, the electronic spectrum and thermodynamic response of three-dimensional laterally coupled InAs–GaAs double quantum dots with disk-, lens-, and cone-shaped morphologies are investigated. The single-electron states are obtained by solving a three-dimensional effective-mass Schrödinger equation with position-dependent mass and confining potential, and the canonical partition function is constructed from the resulting discrete levels to evaluate the entropy and heat capacity as functions of temperature and interdot separation. The evolution of the energy levels with interdot separation reveals the formation of an artificial molecule characterized by an equilibrium length and a dissociation energy that depend on the system morphology. The heat capacity is found to exhibit Schottky-type anomalies and saturation regimes whose position and amplitude are strongly influenced by the quantum-dot shape and the interdot separation. In addition, the heat capacity peak widths as well as the entropy features display a nontrivial interplay between discrete dot levels and the wetting-layer continuum states. These findings demonstrate that the combined control of morphology and lateral spacing provides an efficient route to tailor the electronic and thermodynamic properties of III–V semiconductor double quantum dots for prospective nanoscale device applications.