Abstract At low-temperatures a gas of bosons will undergo phase transition into quantum state matter known as Bose–Einstein condensate (BEC), in which large fraction the particles occupy ground simultaneously. Here we explore performance an endoreversible Otto cycle operating with harmonically confined Bose working medium. We analyze engine operation three regimes, medium BEC phase, and driven across during each cycle. find that unique properties allow for enhanced performance, including...

We studied the efficiency of two different schemes for a quantum heat engine, by considering single Dirac particle trapped in an infinite one-dimensional potential well as ``working substance.'' The first scheme is cycle, composed adiabatic and isoenergetic reversible trajectories configuration space. are driven quasistatic deformation due to external applied force. second variant former, where replaced isothermal ones, along which system contact with macroscopic thermostats. This...

In this work, we study the performance of a quasistatic and quantum-adiabatic magnetic Otto cycles with working substance composed single graphene quantum dot modeled by continuum approach use zigzag boundary condition. Modulating an external or perpendicular field, in approach, found constant behavior total work extracted that is not present formulation. We find that, engine yielded greater terms efficiency as compared its counterpart. case, due to being thermal equilibrium at each point...

We propose an alternative conceptual design for a graphene-based quantum engine, driven by superposition of mechanical strain and external magnetic field. Engineering in nanoscale graphene flake creates gauge field with associated uniform pseudomagnetic The strain-induced can be combined real field, leading to the emergence discrete relativistic Landau levels within single-particle picture. interlevel distance hence their statistical population modulated quasistatically tuning along sequence...

We present an optimal analysis for a quantum mechanical engine working between two energy baths within the framework of relativistic mechanics, adopting first-order correction. This engine, with direct leakage baths, consists adiabatic and isoenergetic processes uses three-level system noninteracting fermions as its substance. Assuming that potential wall moves at finite speed, we derive expression power output and, in particular, reproduce efficiency maximum power.

We studied the efficiency of two different schemes for a magnetically driven quantum heat engine, by considering as ``working substance'' single nonrelativistic particle trapped in cylindrical potential well, presence an external magnetic field. The first scheme is cycle, composed adiabatic and isoenergetic reversible trajectories configuration space. are quasistatic modulation magnetic-field intensity. second variant former, where replaced isothermal ones, along which system contact with...

In this work, we study the conductance and thermoelectric properties of a quantum dot embedded between two metallic leads with side-coupled triple molecule under magnetic field. We focus on spin polarization quantities. Our results show possibility designing an efficient spin-filter device in addition to noticeable enhancement Seebeck coefficient driven by asymmetry energy levels, tunable pure spin-Seebeck effect is obtained. This behavior also holds interacting case, where can be obtained...

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

In this paper, we analyze the total work extracted and efficiency of magnetic Otto cycle in its classic quantum versions. As a general result, found that classical engine is always greater than or equal to counterpart independent working substance. case, due fact substance thermodynamic equilibrium at each point cycle, maximizing energy adiabatic paths. We apply analysis case two-level system, finding Otto's are identical, regardless substance, obtain similar results for multilevel system...

In this work, we report the magnetocaloric effect (MCE) for an electron interacting with antidot, under of Aharonov-Bohm flux (AB-flux) subjected to a parabolic confinement potential. We use Bogachek and Landman model, which additionally allows study quantum dots Fock-Darwin energy levels vanishing antidot radius AB-flux. find that AB-flux strongly controls oscillatory behaviour MCE, thus acting as control parameter cooling or heating effect. propose way detect by measuring temperature differences.

The concept of a quantum heat engine (QHEN) has been discussed in the literature, not only due to its intrinsic scientific interest, but also as an alternative efficiently recover, on nanoscale device, thermal energy form useful work. character QHEN relies, for instance, fact that any intermediate states is determined by density matrix operator. In particular, this can represent mixed state. For classical engine, theoretical upper bound efficiency obtained analyzing quasi-static operation...

This study investigates the anisotropic effects on a system of three qubits with chain and ring topology, described by antiferromagnetic Heisenberg $XXX$ model subjected to homogeneous magnetic field. We explore Stirling Otto cycles find that easy-axis anisotropy significantly enhances engine efficiency across all cases. At low temperatures, configuration outperforms both work during cycle. Additionally, in topologies, cycle achieves Carnot finite at quantum critical points. In contrast,...

We study the effect of degeneracy factor in energy levels well-known Landau problem for a magnetic engine. The scheme cycle is composed two adiabatic processes and isomagnetic processes, driven by quasi-static modulation external field intensity. derive analytical expression relation between temperature along process and, particular, reproduce efficiency as function compression ratio.

In this work, we report the magnetocaloric effect (MCE) in two systems of non-interactive particles: first corresponds to Landau problem case and second an electron a quantum dot subjected parabolic confinement potential. scenario, realize that is totally different from what happens when degeneracy single confined magnetic field not taken into account. particular, system negligible, cools system, while other case, strong, heats up. For study competition between characteristic frequency...

We consider a purely mechanical quantum cycle comprised of adiabatic and isoenergetic processes. In the latter, system interacts with an energy bath keeping constant expectation value Hamiltonian. this work, we study performance for described by Rabi model case controlling coupling strength parameter, resonator frequency, two-level frequency. For cases either parameter or find that it is possible to closely approach maximal unit efficiency when sufficiently increased in first stage....

We study the performance of an endoreversible magnetic Otto cycle with a working substance composed single quantum dot described using well-known Fock–Darwin model. find that tuning intensity parabolic trap (geometrical confinement) impacts proposed cycle’s performance, quantified by power, work, efficiency, and parameter region where operates as engine. demonstrate exists efficiency at maximum output power exceeds Curzon–Ahlborn achieved classical substance.

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

In this paper, we revisit the q-state clock model for small systems. We present results thermodynamics of values from q = 2 to 20 square lattices L × , with ranging 3 64 free-boundary conditions. Energy, specific heat, entropy, and magnetization were measured. found that Berezinskii-Kosterlitz-Thouless (BKT)-like transition appears > 5, regardless lattice size, while at 5 is lost < 10; ≤ 4, BKT never present. phase diagram in terms shows ferromagnetic (FM) paramagnetic (PM) phases critical...

We explore proximity-induced magnetocaloric effect (MCE) on transition metal dichalcogenides, focusing a two-dimensional (2D) ${\mathrm{MoTe}}_{2}$ monolayer deposited ferromagnetic semiconductor EuO substrate connected to heat source. model this heterostructure using tight-binding model, incorporating exchange, and Rashba fields induced by proximity including temperature through Fermi statistics mean-field calculations. The MCE is the 2D layer due substrate, revealing large spin-polarized...

We design a Teaching laboratory experience for blind students, to measure the linear thermal expansion coefficient of an object. use open-source electronic prototyping platform create interactive objects, with conversion visual signals into acoustic that allow student participate at same time as their classmates in session. For it was first he managed normally physics laboratory.

We examine the performance of a finite-time, endoreversible Otto heat engine with working medium monolayer or multilayered graphene subjected to an external magnetic field. As energy spectrum multilayer under field depends strongly on number layers, so too does its thermodynamic behavior. show that this leads simple relationship between efficiency and layers in medium. Furthermore, we find at maximum power for bilayer trilayer mediums can exceed classical cycle. Conversely, displays...

In this work, we report the caloric effect for an electronic system of antidot type, modeled by combining a repulsive and attractive potential (parabolic confinement). system, consider action perpendicular external magnetic field possibility having Aharonov-Bohm flux (AB-flux) generated current passing through solenoid placed inside forbidden zone electron. The energy levels are obtained analytically, model is known as Bogachek Landman model. We propose to control response varying only...