scholarly journals Otto Engine: Classical and Quantum Approach

Entropy ◽  
2020 ◽  
Vol 22 (7) ◽  
pp. 755
Author(s):  
Francisco J. Peña ◽  
Oscar Negrete ◽  
Natalia Cortés ◽  
Patricio Vargas
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Thermodynamic Cycle ◽  
Classical Case ◽  
Total Work ◽  
Otto Cycle ◽  
Level System ◽  
Multilevel System ◽  
Quantum Approach ◽  
Quantum Counterpart

In this paper, we analyze the total work extracted and the efficiency of the magnetic Otto cycle in its classic and quantum versions. As a general result, we found that the work and efficiency of the classical engine is always greater than or equal to its quantum counterpart, independent of the working substance. In the classical case, this is due to the fact that the working substance is always in thermodynamic equilibrium at each point of the cycle, maximizing the energy extracted in the adiabatic paths. We apply this analysis to the case of a two-level system, finding that the work and efficiency in both the Otto’s quantum and classical cycles are identical, regardless of the working substance, and we obtain similar results for a multilevel system where a linear relationship between the spectrum of energies of the working substance and the external magnetic field is fulfilled. Finally, we show an example of a three-level system in which we compare two zones in the entropy diagram as a function of temperature and magnetic field to find which is the most efficient region when performing a thermodynamic cycle. This work provides a practical way to look for temperature and magnetic field zones in the entropy diagram that can maximize the power extracted from an Otto magnetic engine.

scholarly journals Magnetic Otto Engine for an Electron in a Quantum Dot: Classical and Quantum Approach

2019 ◽  
Author(s):  
Francisco J. Peña ◽  
Oscar Negrete ◽  
Gabriel Alvarado Barrios ◽  
David Zambrano ◽  
Alejandro González ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Quantum Dot ◽  
Perpendicular Magnetic Field ◽  
Classical Approach ◽  
Total Work ◽  
Otto Cycle ◽  
Classical Counterpart ◽  
Quantum Approach ◽  
Quantum Version ◽  
Quantum Formulation

We study the performance of a classical and quantum magnetic Otto cycle with a quantum dot as a working substance using the Fock-Darwin model with the inclusion of the Zeeman interaction. Modulating an external/perpendicular magnetic field, we found in the classical approach an oscillating behavior in the total work that is not perceptible under the quantum formulation. Also, we compare the work and efficiency of this system for different regions of the Entropy, $S(T,B)$, diagram where we found that the quantum version of this engine always shows a reduced performance in comparison to his classical counterpart.

scholarly journals Magnetic Otto Engine for an Electron in a Quantum Dot: Classical and Quantum Approach

Entropy ◽  
2019 ◽  
Vol 21 (5) ◽  
pp. 512 ◽  
Author(s):  
Francisco J. Peña ◽  
Oscar Negrete ◽  
Gabriel Alvarado Barrios ◽  
David Zambrano ◽  
Alejandro González ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Thermal Equilibrium ◽  
Classical Case ◽  
Perpendicular Magnetic Field ◽  
Classical Approach ◽  
Total Work ◽  
Otto Cycle ◽  
Single Quantum ◽  
Quantum Approach ◽  
Single Quantum Dot

We studied the performance of classical and quantum magnetic Otto cycle with a working substance composed of a single quantum dot using the Fock–Darwin model with the inclusion of the Zeeman interaction. Modulating an external/perpendicular magnetic field, in the classical approach, we found an oscillating behavior in the total work extracted that was not present in the quantum formulation.We found that, in the classical approach, the engine yielded a greater performance in terms of total work extracted and efficiency than when compared with the quantum approach. This is because, in the classical case, the working substance can be in thermal equilibrium at each point of the cycle, which maximizes the energy extracted in the adiabatic strokes.

Magnetocaloric as Solid-State Cooling Technique for Energy Saving

2020 ◽  
pp. 226-252
Author(s):  
Ciro Aprea ◽  
Adriana Greco ◽  
Angelo Maiorino ◽  
Claudia Masselli
Keyword(s):  
Magnetic Field ◽  
Solid State ◽  
External Magnetic Field ◽  
Magnetocaloric Effect ◽  
Intrinsic Property ◽  
Thermodynamic Cycle ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Cooling Technology ◽  
Active Regeneration

Magnetocaloric is an emerging cooling technology arisen as alternative to vapor compression. The main novelty introduced is the employment of solid-state materials as refrigerants that experiment magnetocaloric effect, an intrinsic property of changing their temperature because of the application of an external magnetic field under adiabatic conditions. The reference thermodynamic cycle is called active magnetocaloric regenerative refrigeration cycle, and it is Brayton-based with active regeneration. In this chapter, this cooling technology is introduced from the fundamental principles up to a description of the state of the art and the goals achieved by researches and investigations.

scholarly journals Zitterbewegung in External Magnetic Field: Classic versus Quantum Approach

2011 ◽  
Vol 41 (8) ◽  
pp. 1355-1374 ◽  
Author(s):  
Mehran Zahiri-Abyaneh ◽  
Mehrdad Farhoudi
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Quantum Approach

scholarly journals Chiral magnetic effect in the presence of electroweak interactions as a quasiclassical phenomenon

2018 ◽  
Vol 33 (07n08) ◽  
pp. 1850043 ◽  
Author(s):  
Maxim Dvornikov ◽  
Victor B. Semikoz
Keyword(s):  
Magnetic Field ◽  
Particle Acceleration ◽  
External Magnetic Field ◽  
Energy Density ◽  
Electric Field ◽  
Electromagnetic Fields ◽  
Magnetic Effect ◽  
Chiral Magnetic Effect ◽  
Electric And Magnetic Fields ◽  
Quantum Approach

We elaborate the quasiclassical approach to obtain the modified chiral magnetic effect (CME) in the case when the massless charged fermions interact with electromagnetic fields and the background matter by the electroweak forces. The derivation of the anomalous current along the external magnetic field involves the study of the energy density evolution of chiral particles in parallel electric and magnetic fields. We consider both the particle acceleration by the external electric field and the contribution of the Adler anomaly. The condition of the validity of this method for the derivation of the CME is formulated. We obtain the expression for the electric current along the external magnetic field, which appears to coincide with our previous results based on the purely quantum approach. Our results are compared with the findings of other authors.

RECOIL IMPLANTATION MÖSSBAUER EXPERIMENT ON 57Fe IN Ge IN THE PRESENCE OF AN EXTERNAL MAGNETIC FIELD

1980 ◽  
Vol 41 (C1) ◽  
pp. C1-445-C1-445
Author(s):  
G. Langouche ◽  
N. S. Dixon ◽  
L. Gettner ◽  
S. S. Hanna
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Recoil Implantation
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