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TT: Fachverband Tiefe Temperaturen
TT 20: Transport: Spincaloric Transport (jointly with MA)
TT 20.11: Vortrag
Montag, 11. März 2013, 17:45–18:00, H22
Quantum Isobaric Process and Thermodynamic Diesel Cycle in Ni2 — •Chuanding Dong, Georgios Lefkidis, and Wolfgang Hübner — Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Box 3049, 67653 Kaiserslautern, Germany
Building thermodynamic cycles with magnetic molecules extends quantum thermodynamics to real systems [1,2] and provides a unique opportunity to explore the thermodynamic properties of the spin degree of freedom. Here we propose a quantum isobaric process in the Ni2 dimer, and build a quantum Diesel engine [3]. The level scheme of Ni2 is obtained using ab-initio calculation and the perturbative inclusion of an external magnetic field. Our isobaric process is realized by adjusting the bath temperature in dependence on the interatomic distance. The boundary condition of keeping the pressure constant imposes a limitation on the allowed bond lengths, which we call isobaric range.
In the quantum Diesel cycle, since the preceding adiabatic process brings the Ni2 dimer to a nonequilibrium state, the isobaric process is realized through a modified Boltzmann distribution. Due to its strong effect on the distribution profile, novel features, such as the crossing of the two adiabatic strokes, can appear on the projection on the two-dimensional P−V diagram.
[1] H. T. Quan, Phys. Rev. E 79, 041129 (2009).
[2] T. D. Kieu, Phys. Rev. Lett. 93, 140403 (2004).
[3] C. D. Dong, G. Lefkidis, and W. Hübner, J. Supercond. Nov. Magn (in press).