Resonant tunneling in anAlxGa1−xAs/GaAs quantum dot as a function of magnetic field

1992 ◽  
Vol 46 (7) ◽  
pp. 3948-3952 ◽  
Author(s):  
M. Tewordt ◽  
L. Martín-Moreno ◽  
V. J. Law ◽  
M. J. Kelly ◽  
R. Newbury ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Quantum Dot ◽  
Resonant Tunneling ◽  
Gaas Quantum Dot

PHOTON-ASSISTED TRANSPORT CHARACTERISTICS THROUGH QUANTUM DOT COUPLED TO SUPERCONDUCTING RESERVOIRS

NANO ◽  
2006 ◽  
Vol 01 (03) ◽  
pp. 259-264 ◽  
Author(s):  
A. S. ATALLAH ◽  
A. H. PHILLIPS ◽  
A. F. AMIN ◽  
M. A. SEMARY
Keyword(s):  
Magnetic Field ◽  
Numerical Calculation ◽  
Quantum Dot ◽  
Resonant Tunneling ◽  
Andreev Reflection ◽  
Point Contact ◽  
Quantum Point Contact ◽  
Time Varying ◽  
Quantum Point ◽  
Tunneling Behavior

The influence of time-varying fields on the transport through a mesoscopic device has been investigated. This mesoscopic device is modeled as a quantum dot coupled to superconducting reservoirs via quantum point contact. The effect of a magnetic field and the Andreev reflection process were taken into account. The conductance was deduced by using Landuaer–Buttiker equation. A numerical calculation has been performed that shows a resonant tunneling behavior. Such investigation is important for fabricating photoelectron mesoscopic devices.

scholarly journals Magnetic field effect on the energy levels of an exciton in a GaAs quantum dot: Application for excitonic lasers

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
K. Luhluh Jahan ◽  
A. Boda ◽  
I. V. Shankar ◽  
Ch. Narasimha Raju ◽  
Ashok Chatterjee
Keyword(s):  
Magnetic Field ◽  
Quantum Dot ◽  
Field Effect ◽  
Energy Levels ◽  
Magnetic Field Effect ◽  
Gaas Quantum Dot

scholarly journals Effect of confinement potential shape on the electronic, thermodynamic, magnetic and transport properties of a GaAs quantum dot at finite temperature

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
K. Luhluh Jahan ◽  
Bahadir Boyacioglu ◽  
Ashok Chatterjee
Keyword(s):  
Magnetic Field ◽  
Heat Capacity ◽  
Quantum Dot ◽  
Transport Properties ◽  
Average Energy ◽  
Persistent Current ◽  
Confinement Potential ◽  
Potential Shape ◽  
Gaas Quantum Dot ◽  
The Magnetic Field

Abstract The effect of the shape of the confinement potential on the electronic, thermodynamic, magnetic and transport properties of a GaAs quantum dot is studied using the power-exponential potential model with steepness parameter p. The average energy, heat capacity, magnetic susceptibility and persistent current are calculated using the canonical ensemble approach at low temperature. It is shown that for soft confinement, the average energy depends strongly on p while it is almost independent of p for hard confinement. The heat capacity is found to be independent of the shape and depth of the confinement potential at low temperatures and for the magnetic field considered. It is shown that the system undergoes a paramagnetic-diamagnetic transition at a critical value of the magnetic field. It is furthermore shown that for low values of the potential depth, the system is always diamagnetic irrespective of the shape of the potential if the magnetic field exceeds a certain value. For a range of the magnetic field, there exists a window of p values in which a re-entrant behavior into the diamagnetic phase can occur. Finally, it is shown that the persistent current in the present quantum dot is diamagnetic in nature and its magnitude increases with the depth of the dot potential but is independent of p for the parameters considered.

Effect of temperature on magnetic susceptibility and thermodynamic properties of an asymmetric quantum dot in tilted magnetic field

2015 ◽  
Vol 29 (23) ◽  
pp. 1550127 ◽  
Author(s):  
R. Khordad
Keyword(s):  
Magnetic Field ◽  
Magnetic Susceptibility ◽  
Quantum Dot ◽  
Specific Heat ◽  
Energy Levels ◽  
Effect Of Temperature ◽  
Magnetic Field Direction ◽  
Asymmetric Quantum ◽  
Gaas Quantum Dot ◽  
The Magnetic Field

In this paper, the specific heat, entropy and magnetic susceptibility of an asymmetric GaAs quantum dot (QD) are studied under the influence of temperature and a tilted external magnetic field. We first calculate the analytical wave functions and energy levels using a transformation to simplify the Hamiltonian of the system. Then, we obtain the analytical expressions for specific heat, entropy and magnetic susceptibility as the function of temperature, magnetic field and its direction for various anisotropy of the system. According to the results obtained from the present work, we find that (i) the specific heat and entropy are decreased when the magnetic field increases. (ii) When anisotropy is increased, the specific heat and entropy decrease. (iii) At large magnetic fields, the anisotropy has not important effect on specific heat and entropy. In briefly, the magnetic field, magnetic field direction and anisotropy play important roles in the specific heat, entropy and magnetic susceptibility of an asymmetric QD.

Magnetic-field-induced quantum Hall—insulator transition and persistent photoconductivity in InAs/GaAs quantum dot layers

2003 ◽  
Vol 17 ◽  
pp. 159-160 ◽  
Author(s):  
Vladimir A. Kulbachinskii ◽  
Roman A. Lunin ◽  
Vasili A. Rogozin ◽  
Vladimir G. Kytin ◽  
Boris N. Zvonkov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Quantum Dot ◽  
Quantum Hall ◽  
Insulator Transition ◽  
Persistent Photoconductivity ◽  
Gaas Quantum Dot

scholarly journals 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

2019 ◽  
Vol 11 (3) ◽  
pp. 76 ◽  
Author(s):  
A. A. Shukri ◽  
F. S. Nammas
Keyword(s):  
Magnetic Field ◽  
Heat Capacity ◽  
Magnetic Properties ◽  
Quantum Dot ◽  
Electron Interaction ◽  
Double Peak Structure ◽  
Peak Structure ◽  
Interacting Electrons ◽  
Gaas Quantum Dot ◽  
Spinless Case

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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