The Asymmetry In Quantum Thermodynamics

Quantum information science is a field that studies information analysis and process-ing based on the principle of quantum mechanics.In recent decades,with the growth and development of concepts such as quantum computation and quantum cryptography,quantum information science has developed a complete research system to explore and control the properties of the world in microscopic scale.As a novel branch of quantum information science,quantum resource theory regards the quantum phenomena as ab-stract resources,and aims to build a unified framework to analyze the transformation characteristics of quantum resources in different information processing scenario.The non-thermality and the asymmetry resources are two important research subjects in the context of resource theory.The non-thermality is the thermodynamic property of deviation from the thermal equilibrium state,and the asymmetry is the property of a system that breaks some con-servation laws.Both of them are the conventional subjects of the classical physics,but they lack the precise characterization in the quantum world.Nevertheless,with the help of quantum resource theory,we can re-interpret the ambiguous concepts in micro-scopic scale from the first principles of quantum physics,and further explore the deep connection between the quantum correspondence of classical concepts such as heat,temperature and entropy.This thesis mainly explores the distinct behaviors of asymmetry or coherence re-source in quantum thermodynamics.As a direct consequence of the energy conserva-tion law in thermodynamics,asymmetric resource is of great importance in both the classification of different quantum thermal operations and the complete description of the laws of quantum thermodynamics.The research method of this thesis is to search the asymmetric resource transformation conditions under various specific resource-free quantum thermal operations,with the tools of quantum information science.This thesis deals with two of our research results.The first part is the translation limit of asymmetry/coherence resource under single-mode thermal operation and enhanced thermal operation.First of all,we propose an experimental friendly thermal operation with single-mode bosonic heat bath.Based on the study of the population and coher-ence dynamics in the low dimensional system,we compare the single-mode thermal operation with other thermal operations under different settings.Next,we derive the tight upper' bound of the coherence merging task,and use the bound to find that the erasing the correlation consumes non-thermal resources in quantum thermodynamics-In the second part-we study the amplification of quantum asymmetry with correlating catalysts.First-we generalize the no-catalysis theorem of asymmetry-and further prove that finite-dimensional pure catalysis cannot enhance the state transformation ability of translation-invariant operation-which indicates the importance of correlation in cat-alytic phenomenon.Then we show that the finite-dimensional correlating catalysis can enhance the ability of translation invariant operations of the asymmetrical qubit sys-tem to nearly all of quantum operations-thus it extends the coherence no-broadcasting theorem which forbid symmetric system to gain any asymmetric resource with finite correlating catalysts.Both results are useful for refining the quantum versions of the laws of thermodynamics in terms of asymmetry.