Evaluation of the thermodynamics of a four level system using canonical density matrix method

• Autorzy: Awoga O. , Ikot A. , Ituen E. , Akpabio L.
• Języki publikacji: EN

Abstrakty

EN

We consider a four-level system with two subsystems coupled by weak interaction. The system is in thermal equilibrium. The thermodynamics of the system, namely internal energy, free energy, entropy and heat capacity, are evaluated using the canonical density matrix by two methods. First by Kronecker product method and later by treating the subsystems separately and then adding the evaluated thermodynamic properties of each subsystem. It is discovered that both methods yield the same result, the results obey the laws of thermodynamics and are the same as earlier obtained results. The results also show that each level of the subsystems introduces a new degree of freedom and increases the entropy of the entire system. We also found that the four-level system predicts a linear relationship between heat capacity and temperature at very low temperatures just as in metals. Our numerical results show the same trend.

Słowa kluczowe

EN

Canonical density matrix; entropy; Kronecker product; Reduced density matrix

PL

entropia; Iloczynem Kroneckera; macierz gęstości; redukcja

• Wydawca: Wydawnictwo Instytutu Maszyn Przepływowych PAN ; Komitet Termodynamiki i Spalania PAN
• Czasopismo: Archives of Thermodynamics
• Rocznik: 2012
• Tom: Vol. 33, no. 4
• Strony: 91--107
• Opis fizyczny: Bibliogr. 30 poz.,

Twórcy

autor

Awoga O.

autor

Ikot A.

autor

Ituen E.

autor

Akpabio L.

• Theoretical Physics Group, Department of Physics, University of Uyo, Nigeria,

Bibliografia

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