Variational calculations of the heat capacity of a semiconductor quantum dot in magnetic fields

Shaer, Ayham; Elsaid, Mohammad K.; El-Hasan, Musa

doi:10.1016/j.cjph.2016.04.024

Cited by 19 publications

(6 citation statements)

References 18 publications

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“…Therefore, one can find a plethora of studies concerned with thermodynamics of LDSN. [33][34][35][36][37][37][38][39][40][41][42][43][44][45] The Shannon entropy is a specific form of the entropy functional widely regarded as the cornerstone of the information-theory-based statistical thermodynamics. [46] The magnetocaloric effect (MCE) is a magneto-thermodynamic phenomenon that can be conceived as an in-built response of the magnetic materials as a result of change in the magnetic field (ΔB) and possesses a straightforward connection with the entropy change (ΔS).…”

Section: Introductionmentioning

confidence: 99%

Harnessing the Shannon Entropy‐Based Magnetocaloric Effect in GaAs Quantum Dot under the Influence of Noise‐Anharmonicity Interplay

Bhakti,

Datta,

Ghosh

2024

Physica Status Solidi (b)

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In the present investigation, the Shannon entropy‐based magnetocaloric effect (MCE) of GaAs quantum dot (QD) is explored under the simultaneous influence of anharmonicity and Gaussian white noise (GWHN). The symmetry of the anharmonic potential (AHP), the manner of incorporation of GWHN, and the QD confinement interplay with great intricacy to tailor the MCE. AHP of odd (even) symmetry reduces (increases) the confinement of the system relative to the anharmonicity‐free system. Generally, the MCE profiles behave in diverse manner under additive white noise and multiplicative white noise and often show deviation from the noise‐free condition. It is also found that additive (multiplicative) noise lowers (raises) the magnitude of MCE in comparison with the noise‐free values.

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Section: Introductionmentioning

confidence: 99%

Harnessing the Shannon Entropy‐Based Magnetocaloric Effect in GaAs Quantum Dot under the Influence of Noise‐Anharmonicity Interplay

Bhakti,

Datta,

Ghosh

2024

Physica Status Solidi (b)

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“…Various theoretical studies have been devoted to solving the Schrodinger equation for the QD system using various approaches such as the variational [13,17,18], the 1/N expansion [11,12], and the exact diagonalization method [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

The Gaussian impurity effect on the electronic and magnetic properties of an electron confined in a lateral quantum dot

Shaer¹,

Elsaid²

2022

Nanosystems: Phys. Chem. Math.

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The Hamiltonian of a single electron trapped in a lateral quantum dot in the influence of an acceptor Gaussian impurity has been solved using a variational wavefunction as a superposition of a product of eigenfunctions of the harmonic oscillator in x and y coordinates. The effects of Gaussian impurity parameters on the system's spectra have been investigated as a function of the magnetic field. Furthermore, the electron probability has been displayed to investigate the impurity position effect on the energy levels. As a second step, the calculated energy spectra were utilized to compute and visualize the system's magnetic properties in the presence of the magnetic field and impurity. The obtained energy spectra show level crossings in the presence of acceptor impurity, which causes oscillations in the magnetic susceptibility and magnetization curves, resulting in an exciting diamagnetic-paramagnetic phase transition. KEYWORDS lateral quantum dot, magnetic properties, Gaussian impurity, diamagnetic-paramagnetic transition FOR CITATION Shaer A., Elsaid M.K. The Gaussian impurity effect on the electronic and magnetic properties of an electron confined in a lateral quantum dot.

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“…Several numerical studies have been applied to QDs to investigate their thermal and magnetic properties (Nammas, Sandouqa, Ghassib, & Al-Sugheir, 2011;Kuros & Okopinska, 2015;Maksym & Chakraborty, 1990;Shaer, Elsaid, & Elhasan, 2016;Climente, Planelles, & Movilla, 2004;Shaer, Elsaid, & Elhasan, n. d.;Boda & Chatterjee, 2014;Mukhopadhyay & Chatterjee, 1999;Merkt, Huser, & Wagner, 1991;Tavernier, Anisimovas, Peeters, Szafran, Adamowski, & Bednarek, 2003;Yang, MacDonald, & Johnson, 1993;Hawrylak, 1993). The diagonalization method was used to explore the effect of e-e interaction on the magnetization and susceptibility of a parabolic GaAs QD with two interacting electrons in the presence of a uniform magnetic field and the spin-Zeeman energy (Boda, Kumar, Sankar, & Chatterjee, 2016).…”

Section: Introductionmentioning

confidence: 99%

“…It was concluded that the oscillatory behavior seen in these magnetic properties is due to singlet-triplet transitions in the ground state which caused by the e-e interaction. A variational method was used to study the heat capacity for two interacting electrons confined in a two-dimensional parabolic QD (2DPQD) and subjected to an external magnetic field (Shaer, Elsaid, & Elhasan, 2016). The main result is that the heat capacity shows a peak structure at low temperature and it saturates in the high temperature region at a specific confining frequency.…”

Section: Introductionmentioning

confidence: 99%

A Comprehensive Study of the Thermal and Magnetic Properties of Two-Harmonically Interacting Electrons Confined in a Parabolic GaAs Quantum Dot in a Magnetic Field

Shukri¹,

Nammas²

2019

APR

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The thermal and magnetic properties of a parabolic GaAs quantum dot for two-Harmonically interacting electrons when it exposed to an external magnetic field, taking into account the spin-Zeeman energy are investigated using the canonical ensemble approach. The effect of spin on these properties is also investigated. With the possibility of a basic and physically sensible model of electron-electron interaction, the issue is precisely soluble. We found a Schottky-like anomaly in the heat capacity at low temperature, while it saturates to the 4kB value as the temperature increases. Also it is noted that entropy enhances with temperature as expected. However as a function of a magnetic field, a peak structure is observed in heat capacity at very low values of magnetic field, while it saturates to the 2kB value as magnetic field increases. Also we noticed that these peaks are not presented in the spinless case. Moreover magnetic field does not show a significant effect on the entropy at high temperatures, but at relatively lower temperatures, the entropy shows a monotonic increase with magnetic field. As a function of the Lande g* factor, we found a local minima and a double peak-structure in the susceptibility and in the heat capacity at g*=0. It is demonstrated that the favored state for both magnetization and susceptibility is the diamagnetic state. The significant effect of the spin on the magnetic properties of quantum dot is seen at low values of temperature and magnetic field. Moreover, our results showed a very good agreement with reported previous works.

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Variational calculations of the heat capacity of a semiconductor quantum dot in magnetic fields

Cited by 19 publications

References 18 publications

Harnessing the Shannon Entropy‐Based Magnetocaloric Effect in GaAs Quantum Dot under the Influence of Noise‐Anharmonicity Interplay

Harnessing the Shannon Entropy‐Based Magnetocaloric Effect in GaAs Quantum Dot under the Influence of Noise‐Anharmonicity Interplay

The Gaussian impurity effect on the electronic and magnetic properties of an electron confined in a lateral quantum dot

A Comprehensive Study of the Thermal and Magnetic Properties of Two-Harmonically Interacting Electrons Confined in a Parabolic GaAs Quantum Dot in a Magnetic Field

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