Quantum physics revolutionized classical disciplines of mechanics, statistical physics, and electrodynamics. One branch scientific knowledge however seems untouched: thermodynamics. Major motivation behind thermodynamics is to develop efficient heat engines. Technology has a trend miniaturize engines, reaching quantum regimes. Development engines (QHEs) requires emerging field Studies QHEs debate whether coherence can be used as resource. We explore an alternative where it function effective...

We consider a finite-time quantum Otto cycle with single- and two spin-$1/2$ systems as its working medium. To mimic adiabatic dynamics at finite time, we employ shortcut-to-adiabaticity technique evaluate the performance of engine including cost shortcut. compare our results true nonadiabatic performances same cycle. Our findings indicate that use scheme significantly enhances compared to counterparts for different figures merit.

We investigate the validity conditions of single-mode approximation (SMA) in a spinor-1 atomic condensate when effects due to residual magnetic fields are negligible. For interactions ferromagnetic type, SMA is shown be exact, with mode function different from what commonly used. However, quantitative deviation small under current experimental (for ${}^{87}\mathrm{Rb}$ atoms). antiferromagnetic interactions, we find that becomes invalid general. The differences among mean-field functions for...

We discuss how a three level system can be used to change the frequency dependent magnetic permeability of an atomic gas significantly different from one. derive conditions for such scheme successful and briefly resulting macroscopic electrodynamics. find that it may possible obtain left handed electrodynamics using levels.

We propose a four-level quantum heat engine in an Otto cycle with working substance of two spins subject to external magnetic field and coupled each other by one-axis twisting spin squeezing nonlinear interaction. calculate the positive work efficiency for different parameter regimes. In particular, we investigate effects correlations at end isochoric processes cycle, as measured entanglement formation discord, on extraction efficiency. The regimes where could enhance are characterized.

Recent experiments have demonstrated an open system realization of the Dicke quantum phase transition in motional degrees freedom optically driven Bose–Einstein condensate a cavity. Relevant collective excitations this light–matter are polaritonic nature, allowing access to critical behavior model through light leaking out This opens path using photodetection-based optical techniques study dynamics and elementary system. We first discuss photon flux observed at cavity face find that it...

We propose a multilevel quantum heat engine with working medium described by generalized Rabi model which consists of two-level system coupled to single-mode bosonic field. The is constructed be continuum limit biological description light-harvesting complexes so that it can amplify coherence mechanism analog classical Huygens clocks. operates in Otto cycle where the baths isochoric processes four-stroke cycle, while either coupling strength or resonance frequency changed adiabatic stages....

We investigate scaling of work and efficiency a photonic Carnot engine with number quantum coherent resources. Specifically, we consider generalization the "phaseonium fuel" for engine, which was first introduced as three-level atom two lower states in superposition by M. O. Scully, Suhail Zubairy, G. S. Agarwal, H. Walther [Science 299, 862 (2003)SCIEAS0036-807510.1126/science.1078955], to case N+1 level atoms N levels. take into account atomic relaxation dephasing well cavity loss derive...

We investigate the absorption and transmission properties of a weak probe field under influence strong control in hybrid cavity magnomechanical system microwave regime. This consists two ferromagnetic material yttrium iron garnet (YIG) spheres strongly coupled to single mode. In addition magnon-induced transparency (MIT) that arise due photon-magnon interactions, we observe magnomechanically induced (MMIT) presence nonlinear phonon-magnon interaction. addition, discuss emergence tunability...

We consider an optomechanical double-ended cavity under the action of a coupling laser and probe in electromagnetically induced transparency configuration. It is shown how group delay advance field can be controlled by power field. In contrast to single-ended cavities, only allowing for superluminal propagation, possibility both subluminal propagation regimes are found. The magnitudes calculated 1ms -2s, respectively, at very low pumping few microwatts. addition, interaction with time...

We consider the dynamics of a collisional model in which both system and environment are embodied by spin-$1/2$ particles. In order to include non-Markovian features our we introduce interactions among environmental qubits investigate effect that different models such interaction have on degree non-Markovianity system's dynamics. By extending beyond nearest-neighbour, enhance A further significant increase can be observed if collective with forthcoming is considered. However, this case...

We propose a quantum heat engine composed of two superconducting transmission line resonators interacting with each other via an optomechanical-like coupling. One resonator is periodically excited by thermal pump. The incoherently driven induces coherent oscillations in the one due to A limit cycle, indicating finite power output, emerges thermodynamical phase space. system implements all-electrical analog photonic piston. Instead mechanical motion, output obtained as electrical charging our...

We investigate the thermodynamic consistency of master equation description heat transport through an optomechanical system attached to two baths, one optical and mechanical. employ three different equations describe this scenario: (i) The standard used in optomechanics, where each bath acts only on resonator that it is physically connected to; (ii) so-called dressed-state equation, mechanical global system; (iii) what we call both baths are treated nonlocally affect subsystems. Our main...

In this paper, we address the question: To what extent is quantum state preparation of multiatom clusters (before they are injected into microwave cavity) instrumental for determining not only kind machine may operate, but also quantitative bounds its performance? Figuratively speaking, if cluster “crude oil”, question is: Which refining process that can deliver a “gasoline” with “specific octane”? We classify coherences or correlations among atoms according to their ability serve as: (i)...

We propose a spin-star network, where central spin-$1/2$ is coupled with XXZ interaction to $N$ outer particles, as quantum fuel. If the network in thermal equilibrium cold bath, spin can have an effective temperature larger than bath one and scaling nonlinearly $N$. The nonlinearity be tuned $N^2, N^3$ or $N^4$ anisotropy parameter of coupling. Using stream central-spin particles pump micromaser cavity, we calculate dynamics cavity field using coarse-grained master equation. Our study...

We investigate a quantum heat engine with working substance of two particles, one spin-1/2 and the other an arbitrary spin (spin s), coupled by Heisenberg exchange interaction, subject to external magnetic field. The operates in Otto cycle. Work harvested cycle its efficiency are calculated using thermodynamical definitions. It is found that has higher efficiencies at spins can harvest work interaction strengths. role coupling s on output thermal studied detail. In addition, operation...

We put forward a quantum-optical model for thermal diode based on heat transfer between two baths through pair of interacting qubits. find that if the qubits are coupled by Raman field induces an anisotropic interaction, flow can become nonreciprocal and undergoes rectification even produce equal dissipation rates qubits, these be identical, i.e., mutually resonant. The is explained four-wave mixing transitions dressed states governed global master equation. two-qubit interaction key to...

We investigate the evolution of a target qubit caused by its multiple random collisions with $N$-qubit clusters. Depending on cluster state, may correspond to effective interaction thermal bath, coherent (laser) drive, or squeezed bath. In cases where relaxes state dynamics can exhibit quantum advantage, whereby target-qubit temperature be scaled up proportionally $N^2$ and thermalization time shortened similar factor, provided appropriate coherence in is prepared non-thermal means. dub...

The precise measurement of low temperatures is significant for both the fundamental understanding physical processes and technological applications. In this work, we present a method low-temperature that improves thermal range sensitivity by generating quantum coherence in thermometer probe. Typically, temperature measurements, probes thermalize with sample being measured. However, use two-level system, or qubit, as our probe prevent direct access to introducing set ancilla qubits an...

Abstract We study a chain of interacting individual quantum systems connected to heat baths at different temperatures on both ends. Starting with the two-system case, we thoroughly investigate conditions for rectification (asymmetric transport), compute thermal conductance, and generalize results longer chains. find that in weak coupling regime can be independent length negative differential conductance occurs. also examine relationship between entanglement entropy production. In strong...

We propose a scheme to enhance the range and precision of ultra-low temperature measurements by employing probe qubit coupled chain ancilla qubits. Specifically, we analyze governed Heisenberg XX Dzyaloshinskii-Moriya (DM) interactions. The limits are characterized evaluating quantum Fisher information (QFI). Our findings demonstrate that achievable bounds, as well number peaks in QFI function temperature, can be controlled adjusting qubits system's model parameters. These results...

This perspective explores various quantum models of consciousness from the viewpoint information science, offering potential ideas and insights. The under consideration can be categorized into three distinct groups based on level at which mechanics might operate within brain: those suggesting that arises electron delocalization microtubules inside neurons, proposing it emerges electromagnetic field surrounding entire neural network, positing originates interactions between individual neurons...

We report the results of coincidence counting experiments at output, a Michelson interferometer using zero-phonon-line emission single molecule 1.4 K. Under continuous wave excitation, we observe absence counts as an indication two-photon interference. This corresponds to observation Hong-Ou-Mandel correlations and proves suitability molecules for applications in linear optics quantum computation.

We show that the temperature of a cavity field can be drastically varied by its interaction with suitably-entangled atom pairs (dimers) traversing under realistic atomic decoherence. To this end we resort to hitherto untapped resource naturally entangled dimers whose state simply controlled via molecular dissociation, collisions forming dimer, or unstable such as positronium. Depending on chosen cavity-field mode driven steady-state is either much lower higher than ambient temperature,...