Heat capacity and entropy of a GaAs quantum dot with Gaussian confinement

Abstract

The heat capacity and entropy effects in a GaAs quantum dot with Gaussian confinement are calculated in the presence of a magnetic field and its interaction with the electron spin using the canonical ensemble approach. It is shown that the heat capacity shows a Schottky-like anomaly at a low temperature, while it approaches a saturation value 2k B as the temperature increases. As a function of the magnetic field, the heat capacity shows a maximum and then reduces to zero. Also the width of the maximum becomes wider with temperature. It is also shown that the heat capacity remains constant up to a certain value of the confinement length beyond which it displays a monotonic increase. However as a function of the confinement strength, though the heat capacity initially shows a significant drop, it remains constant thereafter. At low temperatures like T ¼ 10 and 20 K, the entropy is found to decrease with increasing magnetic field, but at higher temperatures, it remains almost independent of the magnetic field. At high temperatures, entropy shows a monotonic increase with temperature, but at a sufficiently low temperature as the magnetic field decreases, the entropy is found to develop a shoulder which becomes more and more pronounced with decreasing magnetic field. V C 2012 American Institute of Physics.

Thermal and magnetic properties of cylindrical quantum dot with asymmetric confinement

“…There have been several investigations in the past few years on the thermodynamic properties of quantum dots, because of their vast potential for future technological applications [7,10,11]. Liao [11] found the numerical results for the energy levels and heat capacity in the presence of static electric field and quantum confinement.…”

“…De Groote et al [7] calculated the magnetization, susceptibility, and specific heat of helium-like quantum dots. Boyacioglu and Chatterjee [10] studied the specific heat and entropy of GaAs quantum dot with Gaussian confinement in the presence of the spin Zeeman effect. They observed a Schottky-like anomaly in heat capacity at low temperature while it approaches a saturation value of 2k B with increasing temperature.…”

“…Quantum dots can be thought of as artificial atoms where nuclear potential is replaced by confining potential [4,5]. Magneto-optical experiments together with the generalized Kohn theorem suggest that this confining potential would be more or less parabolic in nature [6][7][8], although quantum dots have also been modelled using other confining potentials, such as the finite potential well and Gaussian potential [9][10][11][12][13][14][15].…”

Magnetization of GaAs Parabolic Quantum Dot by Variation Method

“…[20], the authors had used the SFA (static fluctuation approximation) to study the thermodynamic properties of two dimensional GaAs/AlGaAs parabolic QD in a magnetic field. Boyacioglu and Chatterjee [21] had studied the magnetic properties of a single quantum dot confined with a Gaussian potential model. They observed that the magnetization curve shows peaks structure at low temperature.…”

Magnetic Susceptibility of Coupled Double GaAs Quantum Dot in Magnetic Fields

“…[20], the authors used the static fluctuation approximation (SFA) to study the thermodynamic properties of two-dimensional GaAs/AlGaAs parabolic QD in a magnetic field. Boyacioglu and Chatterjee [21] studied the magnetic properties of a single quantum dot confined with a Gaussian potential model. They observed that the magnetization curve shows peaks structure at low temperature.…”