Advances in Physics最新文献

{"title":"Cavity QED with quantum gases: new paradigms in many-body physics","authors":"F. Mivehvar, F. Piazza, T. Donner, H. Ritsch","doi":"10.1080/00018732.2021.1969727","DOIUrl":"https://doi.org/10.1080/00018732.2021.1969727","url":null,"abstract":"We review the recent developments and the current status in the field of quantum-gas cavity QED. Since the first experimental demonstration of atomic self-ordering in a system composed of a Bose–Einstein condensate coupled to a quantized electromagnetic mode of a high-Q optical cavity, the field has rapidly evolved over the past decade. The composite quantum-gas-cavity systems offer the opportunity to implement, simulate, and experimentally test fundamental solid-state Hamiltonians, as well as to realize non-equilibrium many-body phenomena beyond conventional condensed-matter scenarios. This hinges on the unique possibility to design and control in open quantum environments photon-induced tunable-range interaction potentials for the atoms using tailored pump lasers and dynamic cavity fields. Notable examples range from Hubbard-like models with long-range interactions exhibiting a lattice-supersolid phase, over emergent magnetic orderings and quasicrystalline symmetries, to the appearance of dynamic gauge potentials and non-equilibrium topological phases. Experiments have managed to load spin-polarized as well as spinful quantum gases into various cavity geometries and engineer versatile tunable-range atomic interactions. This led to the experimental observation of spontaneous discrete and continuous symmetry breaking with the appearance of soft-modes as well as supersolidity, density and spin self-ordering, dynamic spin-orbit coupling, and non-equilibrium dynamical self-ordered phases among others. In addition, quantum-gas-cavity setups offer new platforms for quantum-enhanced measurements. In this review, starting from an introduction to basic models, we pedagogically summarize a broad range of theoretical developments and put them in perspective with the current and near future state-of-art experiments.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46791454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cuprate superconductors as viewed through a striped lens","authors":"J. Tranquada","doi":"10.1080/00018732.2021.1935698","DOIUrl":"https://doi.org/10.1080/00018732.2021.1935698","url":null,"abstract":"Understanding the electron pairing in hole-doped cuprate superconductors has been a challenge, in particular because the “normal” state from which it evolves is unprecedented. Now, after three and a half decades of research, involving a wide range of experimental characterizations, it is possible to delineate a clear and consistent cuprate story. It starts with doping holes into a charge-transfer insulator, resulting in in-gap states. These states exhibit a pseudogap resulting from the competition between antiferromagnetic superexchange J between nearest-neighbor Cu atoms (a real-space interaction) and the kinetic energy of the doped holes, which, in the absence of interactions, would lead to extended Bloch-wave states whose occupancy is characterized in reciprocal space. To develop some degree of coherence on cooling, the spin and charge correlations must self-organize in a cooperative fashion. A specific example of resulting emergent order is that of spin and charge stripes, as observed in La Ba CuO . While stripe order frustrates bulk superconductivity, it nevertheless develops pairing and superconducting order of an unusual character. The antiphase order of the spin stripes decouples them from the charge stripes, which can be viewed as hole-doped, two-leg, spin- ladders. Established theory tells us that the pairing scale is comparable to the singlet-triplet excitation energy, , on the ladders. To achieve superconducting order, the pair correlations in neighboring ladders must develop phase order. In the presence of spin stripe order, antiphase Josephson coupling can lead to pair-density-wave superconductivity. Alternatively, in-phase superconductivity requires that the spin stripes have an energy gap, which empirically limits the coherent superconducting gap. Hence, superconducting order in the cuprates involves a compromise between the pairing scale, which is maximized at , and phase coherence, which is optimized at . To understand further experimental details, it is necessary to take account of the local variation in hole density resulting from dopant disorder and poor screening of long-range Coulomb interactions. At large hole doping, kinetic energy wins out over J, the regions of intertwined spin and charge correlations become sparse, and the superconductivity disappears. While there are a few experimental mysteries that remain to be resolved, I believe that this story captures the essence of the cuprates.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2021.1935698","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47042105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-Hermitian physics","authors":"Yuto Ashida, Z. Gong, Masahito Ueda","doi":"10.1080/00018732.2021.1876991","DOIUrl":"https://doi.org/10.1080/00018732.2021.1876991","url":null,"abstract":"A review is given on the foundations and applications of non-Hermitian classical and quantum physics. First, key theorems and central concepts in non-Hermitian linear algebra, including Jordan normal form, biorthogonality, exceptional points, pseudo-Hermiticity, and parity-time symmetry, are delineated in a pedagogical and mathematically coherent manner. Building on these, we provide an overview of how diverse classical systems, ranging from photonics, mechanics, electrical circuits, and acoustics to active matter, can be used to simulate non-Hermitian wave physics. In particular, we discuss rich and unique phenomena found therein, such as unidirectional invisibility, enhanced sensitivity, topological energy transfer, coherent perfect absorption, single-mode lasing, and robust biological transport. We then explain in detail how non-Hermitian operators emerge as an effective description of open quantum systems on the basis of the Feshbach projection approach and the quantum trajectory approach. We discuss their applications to physical systems relevant to a variety of fields, including atomic, molecular and optical physics, mesoscopic physics, and nuclear physics with emphasis on prominent phenomena and subjects in quantum regimes, such as quantum resonances, superradiance, the continuous quantum Zeno effect, quantum critical phenomena, Dirac spectra in quantum chromodynamics, and nonunitary conformal field theories. Finally, we introduce the notion of band topology in complex spectra of non-Hermitian systems and present their classifications by providing the proof, first given by this review in a complete manner, as well as a number of instructive examples. Other topics related to non-Hermitian physics, including nonreciprocal transport, speed limits, nonunitary quantum walk, are also reviewed.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2021.1876991","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44599615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Classical dynamical density functional theory: from fundamentals to applications","authors":"M. te Vrugt, H. Löwen, R. Wittkowski","doi":"10.1080/00018732.2020.1854965","DOIUrl":"https://doi.org/10.1080/00018732.2020.1854965","url":null,"abstract":"Classical dynamical density functional theory (DDFT) is one of the cornerstones of modern statistical mechanics. It is an extension of the highly successful method of classical density functional theory (DFT) to nonequilibrium systems. Originally developed for the treatment of simple and complex fluids, DDFT is now applied in fields as diverse as hydrodynamics, materials science, chemistry, biology, and plasma physics. In this review, we give a broad overview over classical DDFT. We explain its theoretical foundations and the ways in which it can be derived. The relations between the different forms of deterministic and stochastic DDFT as well as between DDFT and related theories, such as quantum-mechanical time-dependent DFT, mode coupling theory, and phase field crystal models, are clarified. Moreover, we discuss the wide spectrum of extensions of DDFT, which covers methods with additional order parameters (like extended DDFT), exact approaches (like power functional theory), and systems with more complex dynamics (like active matter). Finally, the large variety of applications, ranging from fluid mechanics and polymer physics to solidification, pattern formation, biophysics, and electrochemistry, is presented.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2020.1854965","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43101280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction","authors":"","doi":"10.1080/00018732.2020.1859069","DOIUrl":"https://doi.org/10.1080/00018732.2020.1859069","url":null,"abstract":"","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2020.1859069","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49401212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Statistical thermodynamics of dislocations in solids","authors":"J. Langer","doi":"10.1080/00018732.2023.2190730","DOIUrl":"https://doi.org/10.1080/00018732.2023.2190730","url":null,"abstract":"The thermodynamic dislocation theory (TDT) is based on two fundamental but unconventional assumptions: first, that the dislocations in a persistently deforming crystalline solid must obey the second law of thermodynamics and thus be described by an effective temperature; and second, that the controlling time scale for deformation of these systems is the inverse of the thermally activated rate at which entangled dislocation lines become unpinned from each other. By use of these first-principles concepts and comparisons with experimental data, I show that this theory achieves new, usefully predictive understandings of strain hardening, yield stresses, shear banding, and brittle and ductile fracture. I argue that it opens new directions for research.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42691892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular quantum materials: electronic phases and charge dynamics in two-dimensional organic solids","authors":"M. Dressel, S. Tomi'c","doi":"10.1080/00018732.2020.1837833","DOIUrl":"https://doi.org/10.1080/00018732.2020.1837833","url":null,"abstract":"This review provides a perspective on recent developments and their implications for our understanding of novel quantum phenomena in the physics of two-dimensional organic solids. We concentrate on the phase transitions and collective response in the charge sector, the importance of coupling of electronic and lattice degrees of freedom and stress an intriguing role of disorder. After a brief introduction to low-dimensional organic solids and their crystallographic structures, we focus on the dimensionality and interactions and emergent quantum phenomena. Important topics of current research in organic matter with sizeable electronic correlations are Mott metal-insulator phase transitions, charge order and ferroelectricity. Highly frustrated two-dimensional systems are established model compounds for studying the quantum spin liquid state and the competition with magnetic long-range order. There are also unique examples of quantum disordered state of magnetic and electric dipoles. Representative experimental results are complemented by current theoretical approaches.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2020.1837833","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48099038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Explosive phenomena in complex networks","authors":"R. D’Souza, J. G'omez-Gardenes, J. Nagler, A. Arenas","doi":"10.1080/00018732.2019.1650450","DOIUrl":"https://doi.org/10.1080/00018732.2019.1650450","url":null,"abstract":"The emergence of large-scale connectivity and synchronization are crucial to the structure, function and failure of many complex socio-technical networks. Thus, there is great interest in analyzing phase transitions to large-scale connectivity and to global synchronization, including how to enhance or delay the onset. These phenomena are traditionally studied as second-order phase transitions where, at the critical threshold, the order parameter increases rapidly but continuously. In 2009, an extremely abrupt transition was found for a network growth process where links compete for addition in an attempt to delay percolation. This observation of ‘explosive percolation’ was ultimately revealed to be a continuous transition in the thermodynamic limit, yet with very atypical finite-size scaling, and it started a surge of work on explosive phenomena and their consequences. Many related models are now shown to yield discontinuous percolation transitions and even hybrid transitions. Explosive percolation enables many other features such as multiple giant components, modular structures, discrete scale invariance and non-self-averaging, relating to properties found in many real phenomena such as explosive epidemics, electric breakdowns and the emergence of molecular life. Models of explosive synchronization provide an analytic framework for the dynamics of abrupt transitions and reveal the interplay between the distribution in natural frequencies and the network structure, with applications ranging from epileptic seizures to waking from anesthesia. Here we review the vast literature on explosive phenomena in networked systems and synthesize the fundamental connections between models and survey the application areas. We attempt to classify explosive phenomena based on underlying mechanisms and to provide a coherent overview and perspective for future research to address the many vital questions that remained unanswered.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2019.1650450","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49153517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic field effects on excited states, charge transport, and electrical polarization in organic semiconductors in spin and orbital regimes","authors":"Hengxing Xu, Miaosheng Wang, Zhi-Gang Yu, Kai Wang, Bin Hu","doi":"10.1080/00018732.2019.1590295","DOIUrl":"https://doi.org/10.1080/00018732.2019.1590295","url":null,"abstract":"Magnetic field can influence photoluminescence, electroluminescence, photocurrent, injection current, and dielectric constant in organic materials, organic–inorganic hybrids, and nanoparticles at room temperature by re-distributing spin populations, generating emerging phenomena including magneto-photoluminescence, magneto-electroluminescence, magneto-photocurrent, magneto-electrical current, and magneto-dielectrics. These so-called intrinsic magnetic field effects (MFEs) can be observed in linear and non-linear regimes under one-photon and two-photon excitations in both low- and high-orbital materials. On the other hand, spin injection can be realized to influence spin-dependent excited states and electrical conduction via organic/ferromagnetic hybrid interface, leading to extrinsic MFEs. In last decades, MFEs have been serving as a unique experimental tool to reveal spin-dependent processes in excited states, electrical transport, and polarization in light-emitting diodes, solar cells, memories, field-effect transistors, and lasing devices. Very recently, they provide critical understanding on the operating mechanisms in advanced organic optoelectronic materials such as thermally activated delayed fluorescence light-emitting materials, non-fullerene photovoltaic bulk-heterojunctions, and organic–inorganic hybrid perovskites. While MFEs were initially realized by operating spin states in organic semiconducting materials with delocalized π electrons under negligible orbital momentum, recent studies indicate that MFEs can also be achieved under strong orbital momentum and Rashba effect in light emission, photovoltaics, and dielectric polarization. The transition of MFEs from the spin regime to the orbital regime creates new opportunities to versatilely control light-emitting, photovoltaic, lasing, and dielectric properties by using long-range Coulomb and short-range spin–spin interactions between orbitals. This article reviews recent progress on MFEs with the focus on elucidating fundamental mechanisms to control optical, electrical, optoelectronic, and polarization behaviors via spin-dependent excited states, electrical transport, and dielectric polarization. In this article both representative experimental results and mainstream theoretical models are presented to understand MFEs in the spin and orbital regimes for organic materials, nanoparticles, and organic–inorganic hybrids under linear and non-linear excitation regimes with emphasis on underlying spin-dependent processes.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2019.1590295","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46794352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Density-functional theory for plutonium","authors":"P. Söderlind, A. Landa, B. Sadigh","doi":"10.1080/00018732.2019.1599554","DOIUrl":"https://doi.org/10.1080/00018732.2019.1599554","url":null,"abstract":"We review developments in the theoretical description and understanding of plutonium in terms of a metal with itinerant (band) 5f electrons. Within this picture most facets of this remarkable and anomalous material are accurately described by first-principle, parameter-free, density-functional-theory (DFT) calculations. We show that the model explains plutonium’s phase stability, elasticity, lattice vibrations, electronic structure, alloy properties, and magnetism. Fluctuations are addressed by means of constrained DFT calculations and new light is shed on the anomalous properties of δ plutonium, including explaining its negative thermal expansion. Effects of alloying and point defects in plutonium are also addressed. It is further emphasized that strong electron correlations, originating from a large intra-atomic Coulomb repulsion (∼4 eV) of the 5f electrons, that has often been assumed for plutonium in the literature, is inconsistent with the experimental phase diagram of plutonium.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2019.1599554","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43139593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}