Temperature-dependent maximization of work and efficiency in a degeneracy-assisted quantum Stirling heat engine

Chatterjee, Sarbani; Koner, Arghadip; Chatterjee, S. N.; Kumar, C. S. Sudheer

doi:10.1103/physreve.103.062109

Cited by 15 publications

(13 citation statements)

References 47 publications

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“…Let us consider a dinuclear metal complex in a d 9 electronic configuration as the working substance to a four-stroke Quantum Stirling cycle [15,23,24,[29][30][31][32][33][34][35][36]. This class of materials can be defined as an ideal realization of coupled 1/2-spins [5,42,45].…”

Section: Dinuclear Metal Complex As Working Substancementioning

confidence: 99%

“…While Carnot and Otto cycles have been exhaustively studied in the past few years, a wide range of other cycles can be generalized for quantum working substances [23]. In particular, the Stirling cycle has attracted the attention of the scientific community as an alternative for the adiabatic cycles [15,23,24,[30][31][32][33][34][35][36]. The Stirling cycle is characterized by four main processes: (i) isothermal expansion, (ii) isochoric cooling, (iii) isothermal compression, and (iv) isochoric heating.…”

Section: Quantum Stirling Cycle In a Metal Complexmentioning

confidence: 99%

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Quantum Stirling engine based on dinuclear metal complexes

Cruz¹,

Sedehi²,

Anka³

et al. 2023

Quantum Sci. Technol.

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Low-dimensional metal complexes are versatile materials with tunable physical and chemical properties that make these systems promising platforms for caloric applications. In this context, this work proposes a quantum Stirling cycle based on a dinuclear metal complex as a working substance. The results show that the quantum cycle operational modes can be managed when considering the change in the magnetic coupling of the material and the temperature of the reservoirs. Moreover, magnetic susceptibility can be used to characterize the heat exchanges of each cycle step and, therefore, its performance. As a proof of concept, the efficiency of the heat engine is obtained from experimental susceptibility data. These results open doors for studying quantum thermodynamic cycles by using metal complexes; and further the development of emerging quantum technologies based on these advanced materials.

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Section: Dinuclear Metal Complex As Working Substancementioning

confidence: 99%

Section: Quantum Stirling Cycle In a Metal Complexmentioning

confidence: 99%

Quantum Stirling engine based on dinuclear metal complexes

Cruz¹,

Sedehi²,

Anka³

et al. 2023

Quantum Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…The actual phase diagrams depend sensitively on whether or not the phase parity is enforced, and thus the device could actually be used as a diagnostics tool for the presence of 4πperiodicity in Josephson junctions. Indeed, the proposal by Scharf et al 370 has already attracted follow up work in the design of engines 372,373 , and in quantum metrology and sensing [374][375][376] .…”

Section: Topological Josephson Heat Enginementioning

confidence: 99%

Quantum thermodynamic devices: from theoretical proposals to experimental reality

Myers,

Abah,

Deffner

2022

Preprint

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“…In quantum confined systems, the discrete energy spectra make the geometry dependence of the physical properties of materials prominent, which were negligible at macroscale [5][6][7][8][9]. Quantum size effect is perhaps the best known of the geometric effects appearing at nanoscale [10][11][12][13] and the importance of the energy quantization and a few-level systems has led to the study of quantum heat machines highlighting the essence of this effect [14][15][16][17][18][19][20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Spectral properties of size-invariant shape transformation

Aydin¹

2023

Preprint

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Size-invariant shape transformation is a technique of changing the shape of a domain while preserving its sizes under the Lebesgue measure. In quantum confined systems, this transformation leads to so-called quantum shape effects in the physical properties of confined particles associated with the Dirichlet spectrum of the confining medium. Here we show that the geometric couplings between levels generated by the size-invariant shape transformations cause nonuniform scaling in the eigenspectra. In particular, the nonuniform level scaling is characterized by two distinct spectral features: lowering of the first eigenvalue (ground state reduction) and changing of the spectral gaps (energy level splitting or degeneracy formation depending on the symmetries). We explain the ground state reduction by the increase in local breadth (i.e. parts of the domain becoming less confined) that is associated with the sphericity of these local portions of the domain. We accurately quantify the sphericity using two different measures: the radius of the inscribed n-sphere and the Hausdorff distance. Due to Rayleigh-Faber-Krahn inequality, the greater the sphericity, the lower the first eigenvalue. Then, level splitting or degeneracy, depending on the symmetries of the initial configuration, becomes a direct consequence of size-invariance dictating the eigenvalues to have the same asymptotic behavior due to Weyl law. Furthermore, we find that the ground state reduction causes a quantum thermal avalanche which is the underlying reason for the peculiar effect of spontaneous transitions to lower entropy states in systems exhibiting the quantum shape effect. Unusual spectral characteristics of size-preserving transformations can assist in designing confinement geometries that could lead to classically inconceivable quantum thermal machines.

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Temperature-dependent maximization of work and efficiency in a degeneracy-assisted quantum Stirling heat engine

Cited by 15 publications

References 47 publications

Quantum Stirling engine based on dinuclear metal complexes

Quantum Stirling engine based on dinuclear metal complexes

Quantum thermodynamic devices: from theoretical proposals to experimental reality

Spectral properties of size-invariant shape transformation

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