內容簡介
The purpose of this book is to provide an introduction to the applications of quantum field theoretic methods to systems out of equilibrium. The reason for adding a book on the subject of quantum field theory is two-fold: the presentation is, to my knowledge, the first to extensively present and apply to non-equilibrium phenomena the real-time approach originally developed by Schwinger, and subsequently applied by Keldysh and others to derive transport equations. Secondly, the aim is to show the universality of the method by applying it to a broad range of phenomena. The book should thus not just be of interest to condensed matter physicists, but to physicists in general as the method is of general interest with applications ranging the whole scale from high-energy to soft condensed matter physics. The universality of the method, as testified by the range of topics covered, reveals that the language of quantum fields is the universal description of fluctuations, be they of quantum nature, thermal or classical stochastic. The book is thus intended as a contribution to unifying the languages used in separate fields of physics, providing a universal tool for describing non-equilibrium states.
內頁插圖
目錄
Preface
1 Quantum fields
1.1 Quantum mechanics
1.2 N-particle system
1.2.1 Identical particles
1.2.2 Kinematics of fermions
1.2.3 Kinematics of bosons
1.2.4 Dynamics and probability current and density
1.3 Fermi field
1.4 Bose field
1.4.1 Phonons
1.4.2 Quantizing a classical field theory
1.5 Occupation number representation
1.6 Summary
2 Operators on the multi-particle state space
2.1 Physical observables
2.2 Probability density and number operators
2.3 Probability current density operator
2.4 Interactions
2.4.1 Two-particle interaction
2.4.2 Fermio boson interaction
2.4.3 Electron-phonon interaction
2.5 The statistical operator
2.6 Summary
3 Quantum dynamics and Greens functions
3.1 Quantum dynamics
3.1.1 The SchrSdinger picture
3.1.2 The Heisenberg picture
3.2 Second quantization
3.3 Greens functions
3.3.1 Physical properties and Greens functions
3.3.2 Stable of one-particle Greens functions
3.4 Equilibrium Greens functions
3.5 Summary
4 Non-equilibrium theory
4.1 The non-equilibrium problem
4.2 Ground state formalism
4.3 Closed time path formalism
4.3.1 Closed time path Greens function
4.3.2 Non-equilibrium perturbation theory
4.3.3 Wicks theorem
4.4 Non-equilibrium diagrammatics
4.4.1 Particles coupled to a classical field
4.4.2 Particles coupled to a stochastic field
4.4.3 Interacting fermions and bosons
4.5 The self-energy
4.5.1 Non-equilibrium Dyson equations
4.5.2 Skeleton diagrams
4.6 Summary
5 Real-time formalism
5.1 Real-time matrix representation
5.2 Real-time diagrammatics
5.2.1 Feynman rules for a scalar potential
5.2.2 Feynman rules for interacting bosons and fermions
5.3 Triagonal and symmetric representations
5.3.1 Fermion-boson coupling
5.3.2 Two-particle interaction
5.4 The real rules: the RAK-rules
5.5 Non-equilibrium Dyscn equations
5.6 Equilibrium Dyscn equation
5.7 Real-time versus imaginary-time formalism
5.7.1 Imaginary-time formalism
5.7.2 Imaginary-time Greens functions
5.7.3 Analytical continuation procedure
5.7.4 Kadanoff-Baym equations
5.8 Summary
6 Linear response theory
6.1 Linear response
6.1.1 Density re~,ponse
6.1.2 Current response
6.1.3 Ccnductivity tensor
6.1.4 Ccnductance
6.2 Linear response cf Greens functions
6.3 Properties cf respone hmctions
6.4 Stability cf the thermal equilibrium ,tate
6.5 Fluctuation-dissipation theorem
6.6 Time-reversal symmetry
6.7 Scattering and correlation functions
6.8 Summary
7 Quantum kinetic equations
7.1 Left-right subtracted Dyson equation
7.2 Wigner or mixed coordinates
7.3 Gradient approximation
7.3.1 Spectral weight function
7.3.2 Quasi-particle approximation
7.4 Impurity scattering
7.4.1 Boltzmannian motion in a random potential
7.4.2 Brownian motion
7.5 Quasi-classical Greens function technique
7.5.1 Electron-phonon interaction
7.5.2 Renormalization of the a.c. conductivity
7.5.3 Excitation representation
7.5.4 Particle conservation
7.5.5 Impurity scattering
7.6 Beyond the quasi-classical approximation
7.6.1 Thermo-electrics and magneto-transport
7.7 Summary
8 Non-equilibrium superconductivity
8.1 BCS-theory
8.1.1 Nambu or particle-hole space
8.1.2 Equations of motion in Nambu Keldysh space
8.1.3 Greens functions and gauge transformations
8.2 Quasi-classical Greens function theory
8.2.1 Normalization condition
8.2.2 Kinetic equation
8.2.3 Spectral densities
8.3 Trajectory Greens functions
8.4 Kinetics in a dirty superconductor
8.4.1 Kinetic equation
8.4.2 Ginzburg-Landau regime
8.5 Charge imbalance
8.6 Summary
9 Diagrammatics and generating functionals
9.1 Diagrammatics
9.1.1 Propagators and vertices
9.1.2 Amplitudes and superposition
9.1.3 Fundamental dynamic relation
9.1.4 Low order diagrams
9.2 Generating functional
9.2.1 Fhnctional differentiation
9.2.2 From diagrammatics to differential equations
9.3 Connection to operator formalism
9.4 Fermions and Grassmann variables
9.5 Generator of connected amplitudes
9.5.1 Source derivative proof
9.5.2 Combinatorial proof
9.5.3 Functional equation for the generator
9.6 One-particle irreducible vertices
9.6.1 Symmetry broken states
9.6.2 Greens functions and one-particle irreducible vertices
9.7 Diagrammatics and action
9.8 Effective action and skeleton diagrams
9.9 Summary
10 Effective action
10.1 Functional integration
10.1.1 Functional Fourier transformation
10.1.2 Gaussian integrals
10.1.3 Fermionic path integrals
10.2 Generators as functional integrals
10.2.1 Euclid versus Minkowski
10.2.2 Wicks theorem and functionals
10.3 Generators and 1PI vacuum diagrams
10.4 1PI loop expansion of the effective action
10.5 Two-particle irreducible effective action
10.5.1 The 2PI loop expansion of the effective action
10.6 Effective action approach to Bose gases
10.6.1 Dilute Bose gases
10.6.2 Effective action formalism for bosons
10.6.3 Homogeneous Bose gas
10.6.4 Renormalization of the interaction
10.6.5 Inhomogeneous Bose gas
10.6.6 Loop expansion for a trapped Bose gas
10.7 Summary
11 Disordered conductors
11.1 Localization
11.1.1 Scaling theory of localization
11.1.2 Coherent backscattering
11.2 Weak localization
11.2.1 Quantum correction to conductivity
11.2.2 Cooperon equation
11.2.3 Quantum interference and the Cooperon
11.2.4 Quantum interference in a magnetic field
……
12 Classical Statistical Dynamics
Appendices
前言/序言
The purpose of this book is to provide an introduction to the applications of quantum field theoretic methods to systems out of equilibrium. The reason for adding a book on the subject of quantum field theory is two-fold: the presentation is, to my knowledge, the first to extensively present and apply to non-equilibrium phenomena the real-time approach originally developed by Schwinger, and subsequently applied by Keldysh and others to derive transport equations. Secondly, the aim is to show the universality of the method by applying it to a broad range of phenomena. The book should thus not just be of interest to condensed matter physicists, but to physicists in general as the method is of general interest with applications ranging the whole scale from high-energy to soft condensed matter physics. The universality of the method, as testified by the range of topics covered, reveals that the language of quantum fields is the universal description of fluctuations, be they of quantum nature, thermal or classical stochastic. The book is thus intended as a contribution to unifying the languages used in separate fields of physics, providing a universal tool for describing non-equilibrium states.
Chapter 1 introduces the basic notions of quantum field theory, the bose and fermi quantum fields operating on the multi-particle state spaces. In Chapter 2, op- erators on the multi-particle space representing physical quantities of a many-body system are constructed. The detailed exposition in these two chapters is intended to ensure the book is self-contained. In Chapter 3, the quantum dynamics of a many-body system is described in terms of its quantum fields and their correla- tion functions, the Greens functions. In Chapter 4, the key formal tool to describe non-equilibrium states is introduced: Schwingers closed time path formulation of non-equilibrium quantum field theory, quantum statistical mechanics. Perturbation theory for non-equilibrium states is constructed starting from the canonical operator formalism presented in the previous chapters. In Chapter 5 we develop the real-time formalism necessary to deal with non-equilibrium states; first in terms of matrices and eventually in terms of two different types of Greens functions. The diagram representation of non-equilibrium perturbation theory is constructed in a way that the different aspects of spectral and quantum kinetic properties appear in a physi- cally transparent and important fashion for non-equilibrium states. The equivalence of the real-time and imaginary-time formalisms are discussed in detail. In Chap- ter 6 we consider the coexistence regime between equilibrium and non-equilibrium states, the linear response regime. In Chapter 7 we develop and apply the quantum kinetic equation approach to the normal state.
好的,這是一份關於《非平衡態量子場論》(Quantum Field Theory Of Non-equilibrium States)的詳細圖書簡介,該簡介著重於該領域的核心概念、曆史發展、關鍵理論框架及其在現代物理學中的重要應用,同時避免提及您所指的特定書名及其內容。 --- 量子場論的動態前沿:非平衡態的深層探索 在理論物理學的廣袤疆域中,量子場論(QFT)無疑占據著核心地位。它成功地將狹義相對論與量子力學完美結閤,構建瞭描述基本粒子及其相互作用的精確框架。然而,傳統的QFT範式,如微擾論和基於真空態的散射分析,主要集中於係統的平衡態或漸近分離的末態。這種處理方式在粒子物理對撞實驗中取得瞭巨大成功,但在麵對宇宙演化、凝聚態係統中的相變、或瞬態物理現象時,其局限性便暴露無遺。 現實世界是動態的、演化的,充滿瞭非平衡狀態。從宇宙大爆炸後的誇剋-膠子等離子體的形成,到材料內部瞬態激發態的産生,再到量子信息處理中係統對外部擾動的響應,理解物質和能量在非平衡條件下的演化機製,已成為當代理論物理學亟待攻剋的堡壘。 本書旨在係統性地梳理和深入探討非平衡態量子場論這一前沿領域,為研究人員提供一個全麵且嚴謹的理論工具箱,用以分析和解決那些超越傳統平衡態假設的復雜物理問題。 第一部分:理論基礎與演化框架的重塑 非平衡態研究的首要挑戰在於如何有效地描述係統隨時間的演化,尤其是在量子層麵。本書首先奠定瞭必要的數學和物理基礎,重點迴顧瞭經典場論中描述時間演化的工具,並將其提升至量子場論的層麵。 1. 擴展的路徑積分與作用量原理: 平衡態的描述通常依賴於歐幾裏得作用量和維剋定理。然而,在實時間演化中,我們需要一個能夠直接處理時間路徑的框架。本書將詳盡介紹實時間路徑積分(Real-Time Path Integrals)的構造,包括其在高頻振蕩下的處理技巧,以及如何將其推廣至包含復雜的(非平庸的)經典背景場或驅動場的係統。特彆地,將深入探討Keldysh-Schwinger形式的有效作用量及其在計算係統時間演化關聯函數中的核心作用。 2. 輸運方程與有效場論的橋梁: 平衡態QFT往往可以轉化為簡單的統計力學問題。但在非平衡態下,我們需要描述粒子密度、能量流等宏觀輸運量。本書將聚焦於介於玻爾茲曼方程與量子場論之間的過渡區域。重點解析如何從微觀的量子動力學齣發,推導齣適用於描述有限溫度和有限密度下輸運現象的量子輸運方程,例如朗道-吉爾曼方程或更一般的玻爾茲曼方程的量子場論修正形式。 3. 費曼圖在實時間的應用: 傳統的費曼圖和微擾論是基於虛時間或漸近態的。在非平衡態下,費曼圖的拓撲結構和傳播子(Propagators)必須進行根本性的修改。本書將詳細闡述開放/閉閤時間路徑上的費曼圖規則,解釋為何單圈(one-loop)計算在實時間場景下會産生額外的、與係統演化曆史相關的項,以及如何利用這些修正的圖來計算響應函數和粒子産生率。 第二部分:關鍵理論方法與數值實現 非平衡態的精確解析解極其罕見,因此發展高效的數值和近似方法至關重要。本部分著重介紹當前最前沿的計算技術。 4. 場平均方法(Mean-Field Approaches): 在許多情況下,係統動力學可以被簡化為背景場或平均場的演化。本書將介紹經典場近似(Classical Field Approximation)的應用,尤其是在宇宙學和高能重離子碰撞等高密度、弱耦閤的領域。同時,將對比討論平均場近似(Mean-Field Approximation)與更精細的隨機時間演化方法的優劣。 5. 自洽演化與閉閤方程: 為瞭在有限時間內描述非平衡動力學,研究者發展瞭多種閉閤理論(Closed Formalisms),例如著名的一環有效作用量方案或隨機時間演化方案。這些方法試圖通過定義一個演化方程來描述有效場或格林函數的演化,從而避免無限的費曼圖重整化。本書將對這些方案的適用範圍、收斂性及其物理圖像進行批判性分析。 6. 格點量子場論(Lattice QFT)的挑戰與機遇: 將格點方法應用於實時間演化是一個著名的難題,主要源於“符號問題”(Sign Problem)。本書將探討繞過或減輕符號問題的最新策略,包括使用解析延拓、重加權技術或引入虛時間截斷的方法,並討論它們在模擬量子退火或量子相變過程中非平衡啓動方麵的潛力。 第三部分:前沿應用與物理場景 非平衡態QFT的應用範圍極其廣泛,橫跨高能物理、凝聚態物理乃至量子信息科學。本書的第三部分將通過具體的物理模型,展示理論框架的強大解釋力。 7. 極端條件下的粒子産生: 在宇宙學暴脹時期或重離子對撞中,強場或高密度環境會導緻真空的劇烈激發,産生大量的粒子對(如真空極化和拓撲激發)。本書將運用非平衡QFT工具,計算拉伸場背景下粒子的對産生率,並探討非阿貝爾規範場在早期宇宙演化中的動力學。 8. 物質的相變與動力學重構: 許多重要的物理現象都涉及係統從一個相態快速躍遷到另一個相態的過程,例如超導體的超快激發或誇剋-膠子等離子體的冷卻。本書將分析這些過程中的臨界動力學,討論拓撲缺陷(如疇壁、渦鏇)的形成和演化,以及拓撲保護的激發態如何響應外部驅動。 9. 量子耗散與開放係統動力學: 在凝聚態和量子光學中,係統通常並非孤立存在,而是與環境(熱浴)相互作用。這引入瞭耗散和退相乾。本書將介紹如何利用開放係統的量子場論框架(如使用林德布拉德方程的場論推廣或使用對相互作用的微擾處理),來描述量子信息在具有熱力學背景的係統中如何演化和弛豫。 結語 非平衡態量子場論是連接微觀基本定律與宏觀復雜現象之間的關鍵橋梁。本書的編寫旨在匯集該領域中經過時間檢驗的理論工具與最新的研究進展,為讀者提供一個清晰、深入且具有操作性的學習路徑。通過掌握這些工具,理論物理學傢將能更有效地探索那些瞬息萬變、充滿活力的量子世界。它不僅是研究高能和宇宙學現象的必備參考,也是理解復雜材料科學和量子信息係統演化的重要理論基石。