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

被引:92
作者
Boyacioglu, B. [1 ]
Chatterjee, A. [2 ]
机构
[1] Ankara Univ, Vocat Sch Hlth, TR-06290 Ankara, Turkey
[2] Univ Hyderabad, Sch Phys, Hyderabad 500046, Andhra Pradesh, India
关键词
SCHRODINGER-EQUATION; MAGNETIC-FIELDS; TRANSITIONS; POTENTIALS; ELECTRONS; SYSTEMS;
D O I
10.1063/1.4759350
中图分类号
O59 [应用物理学];
学科分类号
摘要
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 = 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. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4759350]
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页数:6
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