A Review of Recent Trends in Quantum Thermodynamics and a System’s Behavioural Analysis of the Universe Originating as a Quantum Energy System

This paper combines a review of recent advances in quantum thermodynamics, including work on objective collapse (Zurek’s quantum Darwinism) and quantum gravity (Verlinde’s quantum gravity explanation), with a redefinition of entropy generation as systems’ change process. These concepts are used as systems’ behaviour analysis tools to allow us to revisit Hartle and Hawking’s 1983 quantum universe and develop a hypothesis for how physically a universe starting in a quantum state could evolve into our current universe, based on systems analysis. The outcome of this analysis raises a question: do we already have the elements of a “theory of everything” hiding in plain sight within recent advances in quantum thermodynamics?

The application of quantum coherence as a resource

Quantum coherence is a basic concept in quantum mechanics, representing one of the most fundamental characteristics that distinguishes quantum mechanics from classical physics. Quantum coherence is the basis for multi-particle interference and quantum entanglement. It is also the essential ingredient for various physical phenomena in quantum optics, quantum information, etc. In recent years, with the proposal of a quantum coherence measurement scheme based on a resource theory framework, quantum coherence as a quantum resource has been extensively investigated. This article reviews the resource theories of quantum coherence and introduces the important applications of quantum coherence in quantum computing,quantum information, and interdisciplinary fields, particularly in quantum thermodynamics and quantum biology. Quantum coherence and its applications are still being explored and developed. We hope this review can provide inspiration for relevant research.

A Unified Approach to the Thermodynamics and Quantum Scaling Functions of One-Dimensional Strongly Attractive SU(w) Fermi Gases

We present a unified derivation of the pressure equation of states, thermodynamics and scaling functions for the one-dimensional （1D） strongly attractive Fermi gases with SU（w） symmetry. These physical quantities provide a rigorous understanding on a universality class of quantum criticality characterized by the critical exponents z = 2 and correlation length exponent v= 1/2. Such a universality class of quantum criticality can occur when the Fermi sea of one branch of charge bound states starts to fill or becomes gapped at zero temperature. The quantum critical cone can be determined by the double peaks in specific heat, which serve to mark two crossover temperatures fanning out from the critical point. Our method opens to further study on quantum phases and phase transitions in strongly interacting fermions with large SU （ w） and non-SU （ w ） symmetries in one dimension.

Thermodynamic Performance of Three-Terminal Hybrid Quantum Dot Thermoelectric Devices

We propose four different models of three-terminal quantum dot thermoelectric devices. From general thermodynamic laws, we examine the rew;rsible efficiencies of the four different models. Based on the master equation, the expressions for the efficiency and power output are derived and the corresponding working regions are determined. Moreover, we particularly analyze the performance of a three-terminal hybrid quantum dot refrigerator. The performance characteristic curves and the optimal performance parameters are obtained. Finally, we discuss the influence of the nonradiative effects on the optimal performance parameters in detail.

Microwave Synthesis of CdTe/TGA Quantum Dots and Their Thermodynamic Interaction with Bovine Serum Albumin

The thioglycollic acid（TGA） as a capping agent, CdTe/TGA quantum dots（QDs） with excellent properties were synthesized under microwave irradiation. The TGA/Cd/Te molar ratios, reaction time, temperature and p H are the crucial factors for properties of QDs. The QDs were characterized by UVvis absorption and fluorescence spectra, transmission electron microscopy and Fourier transform infrared spectroscopy. The experimental results show that when the p H value is 11.5 and molar ratio of TGA：Cd：Te is 1.2：1：0.4 at 100 ℃ heating for 15 min, the resulted QDs exhibit a high fluorescence quantum yield of 78%. The fluorescence full width at half maximum（FHMW） of QDs is around 23 nm. The products are spherical with average size of 3-5 nm. There is a strong coordination effect between TGA and Cd2＋. Moreover, the results of interaction between as-made QDs and bovine serum albumin（BSA） suggest that the QDs-BSA binding reaction is a static quenching. The negative values of free energy（△G〈0） suggest that the binding process is spontaneous, △H〈0 and △S〈0 show that hydrogen bonds and van der Waals interactions play a major role in the binding reaction between QDs and BSA.

Nonequilibrium thermodynamics in cavity optomechanics

Classical thermodynamics has been a great achievement in dealing with systems that are in equilibrium or near equilibrium.As an emerging field,nonequilibrium thermodynamics provides a general framework for understanding the nonequilibrium processes,particularly in small systems that are typically far-from-equilibrium and are dominated by thermal or quantum fluctuations.Cavity optomechanical systems hold great promise among the various experimental platforms for studying nonequilibrium thermodynamics owing to their high controllability,excellent mechanical performance,and ability to operate deep in the quantum regime.Here,we present an overview of the recent advances in nonequilibrium thermodynamics with cavity optomechanical systems.The experimental results in entropy production assessment,fluctuation theorems,heat transfer,and heat engines are highlighted.

Thermal properties of Lense-Thirring spacetime in tetrad theory of gravity

Using the divergence term appearing in the Lagrangian of the teleparallel equivalent of general relativity （TEGR）, we calculate the thermodynamic quantities of four tetrads＇ spacetime reproducing Lense-Thirring （LT） metric. We also investigate the first law of thermodynamics and the quantum statistical relation.

On a tilted Liouville-master equation of open quantum systems

A tilted Liouville-master equation in Hilbert space is presented for Markovian open quantum systems.We demonstrate that it is the unraveling of the tilted quantum master equation.The latter is widely used in the analysis and calculations of stochastic thermodynamic quantities in quantum stochastic thermodynamics.

Influence of an indefinite causal order on an Otto heat engine

The quantum effect plays an important role in quantum thermodynamics,and recently the application of an indefinite causal order to quantum thermodynamics has attracted much attention.Based on two trapped ions,we propose a scheme to add an indefinite causal order to the isochoric cooling stroke of an Otto engine through reservoir engineering.Then,we observe that the quasi-static efficiency of this heat engine is far beyond the efficiency of a normal Otto heat engine and may reach one.When the power is its maximum,the efficiency is also much higher than that of a normal Otto heat engine.This enhancement may originate from the nonequilibrium of the reservoir and the measurement on the control qubit.