Computational materials science from first principles

The Jahn-Teller effect is one of the most fascinating phenomena in modern physics and chemistry, providing a general approach to understanding the properties of molecules and crystals and their origins. The effect inspired one of the most important recent scientific discoveries, the concept of high-temperature superconductivity. This comprehensive volume presents the background of the theory and its main applications in physics and chemistry, along with more recent achievements. Full descriptions are presented alongside thorough references to original material. The 2006 book contains over 200 figures to aid visual explanation and avoids bulky mathematical deductions and overly technical language. It is intended for graduate students and academic researchers working in solid state physics, quantum chemistry, crystallography, spectroscopy, and materials science.

The technique of stimulated Raman adiabatic passage (STIRAP), which allows\nefficient and selective population transfer between quantum states without\nsuffering loss due to spontaneous emission, was introduced in 1990 (Gaubatz\n\\emph{et al.}, J. Chem. Phys. \\textbf{92}, 5363, 1990). Since then STIRAP has\nemerged as an enabling methodology with widespread successful applications in\nmany fields of physics, chemistry and beyond. This article reviews the many\napplications of STIRAP emphasizing the developments since 2000, the time when\nthe last major review on the topic was written (Vitanov \\emph{et al.}, Adv. At.\nMol. Opt. Phys. \\textbf{46}, 55, 2001). A brief introduction into the theory of\nSTIRAP and the early applications for population transfer within three-level\nsystems is followed by the discussion of several extensions to multi-level\nsystems, including multistate chains and tripod systems. The main emphasis is\non the wide range of applications in atomic and molecular physics (including\natom optics, cavity quantum electrodynamics, formation of ultracold molecules,\nprecision experiments, etc.), quantum information (including single- and\ntwo-qubit gates, entangled-state preparation, etc.), solid-state physics\n(including processes in doped crystals, nitrogen-vacancy centers,\nsuperconducting circuits, etc.), and even some applications in classical\nphysics (including waveguide optics, frequency conversion, polarization optics,\netc.). Promising new prospects for STIRAP are also presented (including\nprocesses in optomechanics, detection of parity violation in molecules,\nspectroscopy of core-nonpenetrating Rydberg states, and population transfer\nwith X-ray pulses).\n

مقدمه: اصول و قوانین، نقش بیان اساسی‌ترین ایده‌ها در یک علم و نیز ایجاد چارچوب و روش‌شناسی برای حل مسائل آن علم را بازی می‌کنند. این مقاله بر آن است تا با گذری بر مفاهیم و مراتب چهارگانه سیبرنتیک، به بررسی اصول حاکم بر این علم بر اساس رویکردهای فیزیک جدید و قدیم بپردازد. روش‌: در نگارش مقاله رویکرد مروری‌تحلیلی مورد استفاده قرار گرفته است. این مقاله سعی دارد با بررسی متون علمی این حوزه از طریق روش کتابخانه‌ای، ابتدا گذری بر مفاهیم و مراتب چهارگانه سیبرنتیک داشته باشد، سپس اصول حاکم بر این علم از دو دیدگاه پوزیتیویستی و هرمنوتیکی بررسی نماید. یافته ها: نحوه نگرش به جهان هستی موجب شکل‌گیری دیدگاه‌های مختلف در علم و در عین حال پیشرفت شناخت علمی شده‌است. در ابتدا دیدگاه پوزیتویستی بر اساس تئوری نیوتون و دیدگاه مکانیکی شکل گرفت. سپس پسا اثبات‌گرایان با توجه به دو اصل ضرورت و تصادف قوانین زیست‌شناسی را پی‌ریزی کردند. با ورود تئوری کوانتوم و نسبیت به عرصه فیزیک و آشکار شدن ناتوانی‌های فیزیک کلاسیک در چند مورد، برداشت از جهان و پدیده‌های آن به‌کلی متحول شد. گذر از فیزیک نیوتنی (فیزیک قدیم) به فیزیک کوانتومی (فیزیک جدید)، تحول تئوریک و فلسفی را موجب گردید. در سایه این چرخش، مبانی تئوریک علوم مختلف نیز دگرگون گردید. سیبرنتیک نیز از این نگاه متحولانه بهره‌مند شده‌است. تحلیل متون نشان می‌دهد، بن‌مایه فکری نسل‌ها و اصول سیبرنتیک آمیزه‌ای از رویکردهای پوزیتویستی، ارگانیستی، جهان‌بینی سیستمی، و فیزیک جدید است. بحث و نتیجه گیری: راه‌حل‌های معمول سنتی دیگر جواب‌گوی آشفتگی‌های موجود در دنیای کنونی نیست و به راه‌حل‌های جدیدی نیازمندیم تا بتوانیم پیچیدگی‌های موجود در این دنیا و عصر حاضر را کنترل نماییم. سیبرنتیک یکی از این راه‌حل‌هاست. تفاوت در نوع نگاه به مفهوم مشاهده و مشاهده‌گر است که باعث شکل‌گیری رویکردهای متفاوت و جهان‌بینی‌های مختلف در علوم و متعاقب آن سیبرنتیک شده است. تا جایی که نقطه عطف شکل‌گیری فیزیک جدید را می‌توان مداخله دادن مشاهده‌گر در رویداد دانست. جهانی که در آن مشاهده‌کننده جدای از آنچه مشاهده می‌کند نیست، بلکه قسمتی از همان پدیده‌ است در حالی که در فیزیک کلاسیک تمام پدیده‌ها مستقل از مشاهده‌گر همچون ساعتی دقیق و قانون‌مدار با نظم و ترتیب خاص رخ می‌دهند. بنابراین می توان گفت بن‌مایه فکری نسل‌ها و اصول سیبرنتیک آینده‌ای از رویکردهای پوزیتویستی، ارگانیستی، جهان‌بینی سیستمی و فیزیک جدید است. بر این اساس رویکردی سیبرنتیکی در طی عمر کوتاه آن متکی بر دیدگاه‌های حاکم متحول شده است.

Experimental and theoretical investigations have been carried out in a broad area of low temperature and solid state physics which includes superconductivity, theory of quantum crystals, magnetism in metals, and liquid helium. The pair-field susceptibility of a superconductor has been determined both above and below T/sub c/. Anomalies in the heat capacity in the vicinity of T/sub c/ have been observed in thin superconducting films. The theory of quantum crystals has been applied to the problem of the ground state properties of nucleon matter. The results imply that most of the neutron matter in every neutron star is in the crystalline phase. Enhanced hyperfine nuclear cooling of PrCu/sub 6/ has been used successfully to achieve temperatures to at least 3 mK with slow warmup. Measurements on local moments in metals using nuclear orientation are being carried out at these temperatures. Preliminary results have been obtained in measurements of the differential osmotic pressure in the critical region of /sup 3/He//sup 4/He mixtures. Evidence has been found for surface film superfluidity in mixtures in regions of the phase diagram where the bulk liquid is normal. A new ac technique has been developed to study superfluid flow through fine channels in a manner analogous to the study of I-- V characteristics of superconducting weak links. (auth)

ZnO tetrapod materials for functional applications

Experimental investigations are being carried out in a broad area of low- temperature and solid-state physics which includes superconductivity, magnetism in metals and liquid and solid helium. The pair-field susceptibility of superconductors is being studied. A propagating mode in the phase of the superconducting order parameter has been found. Heat capacities of superconducting films in the vicinity of T/sub c/ are also being investigated. An investigation in the time-dependent high conductivity of dilute solid solutions of sodium in ammonia has been initiated. Nuclear orientation studies of the dilute magnetic impurity problem in metals in the 1 mK temperature region are being carried out. Refrigeration requirements for this work are being met using enhanced hyperfine nuclear cooling. Measurements of the differential osmotic pressure of $sup 3$He/$sup 4$He liquid mixtures near the tricritical point have shown a peak in the ''concentration susceptibility'' at the lambda line. Data obey a simple tricritical scaling relation. The dynamics of superfluid flow through submicron pores are being studied in both pure $sup 4$He and in $sup 3$He/$sup 4$He mixtures in an apparatus provided with a $sup 3$He refrigerator. The quantization of circulation in superfluid liquid $sup 4$He is being investigated using the Vinen method. The low temperature heat capacity of bcc solid $sup 3$He is being studied. (auth)

The problem of emergence in physical theories makes necessary to build a\ngeneral theory of the relationships between the observed system and the\nobserving system. It can be shown that there exists a correspondence between\nclassical systems and computational dynamics according to the Shannon-Turing\nmodel. A classical system is an informational closed system with respect to the\nobserver; this characterizes the emergent processes in classical physics as\nphenomenological emergence. In quantum systems, the analysis based on the\ncomputation theory fails. It is here shown that a quantum system is an\ninformational open system with respect to the observer and able to exhibit\nprocesses of observational, radical emergence. Finally, we take into\nconsideration the role of computation in describing the physical world.\n

Light. Volume 2. Laser Light Dynamics. By H. Haken. (Amsterdam, New York, Oxford: North-Holland, 1985.) [Pp. xxiii + 336 + subject index.] Price Dfl. 125·00/US $46.25 hard cover. Electronic Structure and Electronic Transitions in Layered Materials. Edited by V. Grasso. (Dordrecht, Boston, Lancaster: D. Reidel, 1986.) [Pp. ix + 491 + author and subject index.] Price Dfl.225.00 hard cover. The Physics and Fabrication of Microstructures and Microdevices. Edited by M. J. Kelly and C. Weisbuch. (Berlin, Heidelberg, New York: Springer-Verlag, 1986.) [Pp. xi + 460.1 Price DM 99·00 hard cover. Unitary Transformations in Solid State Physics. By M. Wagner. (Amsterdam, Oxford, New York: North-Holland, 1986.) [Pp. xvi + 341 + author and subject index.] Price Dfl.225.00 hard cover. Differential Manifolds and Theoretical Physics. By W. D. Curtis and F. R. Miller. (Orlando, San Diego and New York: Academic Press, 1985.) [Pp. xiii + 388 + subject index.] Price £69·00 hard cover. Coherent States. Applications in Physics and Mathematical Physics. By J. R. Klauder and B. Skagerstam. (Singapore: World Scientific, 1985.) [Pp. xvii + 911.] Price £6670 soft cover. (69 reprints from various journals + introduction.) International Tables for Crystallography. Edited by T. Hahn. (Dordrecht, Boston, Lancaster: D. Reidel, 1985.) [Pp. viii +119.1 Price £9·00 soft cover. (Brief Teaching Edition of Volume A—Space-Group Symmetry.) Multiple Time Scales. Edited by J. U. Brackbill and B. I. Cohen. (Orlando, San Diego, New York: Academic Press, 1985.) [Pp. xiii + 436 + subject index.] Price ·65.00 hard cover. (Thirteen reviews of applications in physics.) Silicon-on-Insulator: Its Technology and Applications. Edited by S. Furukawa. (Dordrecht, Boston, London: D. Reidel; and Tokyo: KTK Scientific Publishers, 1985.) [Pp. vii + 295 + author index.] Price £49·95 hard cover. (20 papers presented at the seminar on ‘Solid Phase Epitaxy and Interface Kinetics’ held in Oiso, Japan, June, 1983.) Layered Structures and Interface Kinetics: Their Technology and Applications. Edited by S. Furukawa. (Dordrecht, Boston, London: D. Reidel; and Tokyo: KTK Scientific Publishers, 1985.) [Pp. viii + 367 + author index.] Price £60·95 hard cover. (22 papers presented at the seminar on ‘Solid Phase Epitaxy and Interface Kinetics’ held in Oiso, Japan, June, 1983.) Superlattices and Microstructures. Volume 1. Number 1. Edited by J. D. Dow. (Orlando, London, New York: Academic Press, 1985.) [Pp. 96.] soft cover. (New interdisciplinary journal devoted to the physics, chemistry, materials science and electrical engineering of submicron structures not only in semiconductors but also in materials with metallic, insulating and superconducting properties.) Solid Clues. Quantum Physics, Molecular Biology, and the Future of Science. By G. Feinberg. (London: Heinemann, 1985.) [Pp. i + 278 + subject index.] Price £12·95 hard cover. Laser Spectroscopy of Solids. Second Printing. Edited by W. M. Yen and P. M. Selzer. (Berlin, Heidelberg, New York: Springer-Verlag, 1986.) [Pp. xiv + 311 + subject index.] Price DM79 soft cover (See Phil. Mag. B, 44, 185 for review.)

Generating field-free (non-stationary) orientation of molecules in space has been a longstanding goal in the field of quantum control of molecular rotation, which has significant applications in physical chemistry, chemical physics, strong-field physics, and quantum information science. In this Perspective, we review and examine several representative control schemes developed in recent years and implemented in theoretical and experimental areas for generating field-free orientation of molecules. By conducting numerical simulations of different control schemes on the same molecular system, we demonstrate that quantum coherent control, specifically targeting a limited number of the lowest-lying rotational levels to achieve an optimal superposition, can result in a high degree of orientation. To this end, we provide an overview of our latest developed analytical method, which enables the precise design of terahertz field parameters through resonant excitation. This design approach facilitates the attainment of desired field-free orientations by optimizing the amplitudes and phases of rotational wave functions for the selected rotational levels. Finally, we outlook the significance of such progress in multiple frontier research fields, highlighting its potential applications in ultracold physics, quantum computation, quantum simulation, and quantum metrology.

Information is physical: the laws which govern its encoding, processing and communication are those of its unavoidable physical embodyment. In today's computing, information obeys the laws of Newton's and Maxwell's classical physics: this assertion holds all the way from commercial computers down to their most abstract models, e.g. Turing machines and lambda-calculi. Today's computation is classical.Research in quantum information processing and communication (QIPC) was born some twenty years ago, as a child of two major scientific achievements of the 20th century, namely quantum physics and information sciences. The driving force of this interdisciplinary research is that of looking for the consequences of having information encoding, computation and communication obey the laws of quantum physics, i.e. the ultimate knowledge that we have, today, of the foreign world of elementary particles, as described by quantum mechanics. Breakthroughs in algorithmics, cryptography, information theory and abstract computational models have shown that this rerooting of information from classical to quantum has far reaching consequences, both quantitative and qualitative, and opens new avenues for research within the foundations of computer science.The aim of this tutorial is to give a survey of the principles, main results and long term perspectives of current research in QIPC, from a computer science point of view. No prior knowledge in quantum mechanics is required to follow this tutorial. There will be two parts:1 - Computation, the quantum way: quantum bits and quantum operations; two major quantum algorithms: quadratic speedup for unordered database search (Grover's algorithm), exponential speedup for integer factoring (Shor's algorithm);2 - Communication, the quantum way, and longer term perspectives: quantum state teleportation; a quantum cryptographic protocol for secret key distribution. Hot topics in QIPC research, state of the art in physical implementation of quantum computers.

One of the fundamental problems in simulating the motion of sharp interfaces between immiscible fluids is a description of the transition that occurs when the interfaces merge and reconnect. It is well known that classical methods involving sharp interfaces fail to describe this type of phenomena. Following some previous work in this area, we suggest a physically motivated regularization of the Euler equations which allows topological transitions to occur smoothly. In this model, the sharp interface is replaced by a narrow transition layer across which the fluids may mix. The model describes a flow of a binary mixture, and the internal structure of the interface is determined by both diffusion and motion. An advantage of our regularization is that it automatically yields a continuous description of surface tension, which can play an important role in topological transitions. An additional scalar field is introduced to describe the concentration of one of the fluid components and the resulting system of equations couples the Euler (or Navier–Stokes) and the Cahn–Hilliard equations. The model takes into account weak non–locality (dispersion) associated with an internal length scale and localized dissipation due to mixing. The non–locality introduces a dimensional surface energy; dissipation is added to handle the loss of regularity of solutions to the sharp interface equations and to provide a mechanism for topological changes. In particular, we study a non–trivial limit when both components are incompressible, the pressure is kinematic but the velocity field is non–solenoidal (quasi–incompressibility). To demonstrate the effects of quasi–incompressibility, we analyse the linear stage of spinodal decomposition in one dimension. We show that when the densities of the fluids are not perfectly matched, the evolution of the concentration field causes fluid motion even if the fluids are inviscid. In the limit of infinitely thin and well–separated interfacial layers, an appropriately scaled quasi–incompressible Euler–Cahn–Hilliard system converges to the classical sharp interface model. In order to investigate the behaviour of the model outside the range of parameters where the sharp interface approximation is sufficient, we consider a simple example of a change of topology and show that the model permits the transition to occur without an associated singularity.

When solid state physics emerged in the 1940s, its name was controversial. By the 1970s, some physicists came to prefer “condensed matter” as a way to identify the discipline of physics examining complex matter. Physicists and historians often gloss this transition as a simple rebranding of a problematically named field, but attention to the motives behind these names reveals telling nuances. “Solid state physics” and “condensed matter physics”—along with “materials science,” which also emerged during the Cold War—were named in accordance with ideological commitments about the identity of physics. Historians, therefore, can profitably understand solid state and condensed matter physics as distinct disciplines. Condensed matter, rather than being continuous with solid state physics, should be considered alongside materials science as an outlet for specific frustrations with the way solid state was organized.

On the Fer expansion: Applications in solid-state nuclear magnetic resonance and physics

This article examines the need for a comprehensive theory that explains the creation of the universe and the enigmatic behaviours observed in quantum particles. Recent advancements in quantum physics have revealed phenomena in the microscopic and macroscopic realms that challenge conventional explanations based solely on natural laws. This article introduces an argument centred on the concept of “presence of metaphysics in physics” as a means to provide a plausible account for the improbable existence of the universe and the mechanics of the space-time continuum. By incorporating ontological principles in classical physics and quantum mechanics, this proposed model sheds light on the origins of natural laws while also considering the mysterious balance and intricacies observed in micro and macrocosms. Moreover, this article argues that a mere succession of random events guided by mathematical probabilities cannot adequately establish and govern the natural laws that appear to have arisen with the aim of fostering life within the universe.

This paper discovers that current variational principle and Noether theorem for different physics systems with (in) finite freedom systems have missed the double extremum processes of the general extremum functional that both is deduced by variational principle and is necessarily taken in deducing all the physics laws, but these have not been corrected for over a century since Noether's proposing her famous theorem, which result in the crisis deducing relevant mathematical laws and all physics laws. This paper discovers there is the hidden logic cycle that one assumes Euler-Lagrange equations, and then he finally deduces Euler-Lagrange equations via the equivalent relation in the whole processes in all relevant current references. This paper corrects the current key mistakes that when physics systems choose the variational extreme values, the appearing processes of the physics systems are real physics processes, otherwise, are virtual processes in all current articles, reviews and (text) books. The real physics should be after choosing the variational extreme values of physics systems, the general extremum functional of the physics systems needs to further choose the minimum absolute extremum zero of the general extremum functional, otherwise, the appearing processes of physics systems are still virtual processes. Using the double extremum processes of the general extremum functionals, the crisis and the hidden logic cycle in current variational principle and current Noether theorem are solved. Furthermore, the new mathematical and physical double extremum processes and their new mathematical pictures and physics for (in) finite freedom systems are discovered. This paper gives both general variational principle and general Noether theorem as well as their classical and quantum new physics, which would rewrite all relevant current different branches of science, as key tools of studying and processing them.