Part I. Fundamental Concepts: 1. Introduction and overview 2. Introduction to quantum mechanics 3. Introduction to computer science Part II. Quantum Computation: 4. Quantum circuits 5. The quantum Fourier transform and its application 6. Quantum search algorithms 7. Quantum computers: physical realization Part III. Quantum Information: 8. Quantum noise and quantum operations 9. Distance measures for quantum information 10. Quantum error-correction 11. Entropy and information 12. Quantum information theory Appendices References Index.

Quantum Computation and Quantum Information

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

A digital computer is generally believed to be an efficient universal computing device; that is, it is believed able to simulate any physical computing device with an increase in computation time by at most a polynomial factor. This may not be true when quantum mechanics is taken into consideration. This paper considers factoring integers and finding discrete logarithms, two problems which are generally thought to be hard on a classical computer and which have been used as the basis of several proposed cryptosystems. Efficient randomized algorithms are given for these two problems on a hypothetical quantum computer. These algorithms take a number of steps polynomial in the input size, e.g., the number of digits of the integer to be factored.

Polynomial-Time Algorithms for Prime Factorization and Discrete Logarithms on a Quantum Computer

This chapter describes the possibility of simulating physics in the classical approximation, a thing which is usually described by local differential equations. But the physical world is quantum mechanical, and therefore the proper problem is the simulation of quantum physics. A computer which will give the same probabilities as the quantum system does. The present theory of physics allows space to go down into infinitesimal distances, wavelengths to get infinitely great, terms to be summed in infinite order, and so forth; and therefore, if this proposition is right, physical law is wrong. Quantum theory and quantizing is a very specific type of theory. The chapter talks about the possibility that there is to be an exact simulation, that the computer will do exactly the same as nature. There are interesting philosophical questions about reasoning, and relationship, observation, and measurement and so on, which computers have stimulated people to think about anew, with new types of thinking.

/pdf/simulating-physics-with-computers-11bt3yutby.pdf

Simulating physics with computers

CHARMM (Chemistry at HARvard Molecular Mechanics) is a highly versatile and widely used molecu- lar simulation program. It has been developed over the last three decades with a primary focus on molecules of bio- logical interest, including proteins, peptides, lipids, nucleic acids, carbohydrates, and small molecule ligands, as they occur in solution, crystals, and membrane environments. For the study of such systems, the program provides a large suite of computational tools that include numerous conformational and path sampling methods, free energy estima- tors, molecular minimization, dynamics, and analysis techniques, and model-building capabilities. The CHARMM program is applicable to problems involving a much broader class of many-particle systems. Calculations with CHARMM can be performed using a number of different energy functions and models, from mixed quantum mechanical-molecular mechanical force fields, to all-atom classical potential energy functions with explicit solvent and various boundary conditions, to implicit solvent and membrane models. The program has been ported to numer- ous platforms in both serial and parallel architectures. This article provides an overview of the program as it exists today with an emphasis on developments since the publication of the original CHARMM article in 1983.

/pdf/charmm-the-biomolecular-simulation-program-4kexem0xkx.pdf

CHARMM: the biomolecular simulation program.

We describe a collection of techniques whereby audiovisual or other recordings of significant events can be made in a way that hinders falsification, pre-dating, or post-dating by interested parties, even by the makers and operators of the recording equipment. A central feature of these techniques is the interplay between private information, which by its nature is untrustworthy and susceptible to suppression or manipulation by interested parties, and public information, which is too widely known to be manipulated by anyone. While authenticated recordings may be infeasible to falsify, they can be abused in other ways, such as being used for blackmail or harassment; but susceptibility to these abuses can be reduced by encryption and secret sharing.

Improvements to time bracketed authentication

The quantum principles of superposition and entanglement have led to a recasting of the foundations of information and computation theory, and are especially helpful in understanding the nature of privacy. The most private information, exemplified by a quantum eraser experiment, is best regarded as existing only conditionally and temporarily—after the experiment is over no trace remains. Less private is classically‐secret information—quantum information that has decohered, and thus become recoverable in principle, though not in practice, from portions of the environment. Finally there is public information, which has been replicated so thoroughly throughout the environment as to be infeasible to conceal. The Internet has caused an explosion of public information, with the beneficial side effect of making it harder for despots to rewrite the history of their misdeeds, and it is tempting to hope that all macroscopic information is permanent, making such cover‐ups impossible in principle if not in practice. ...

Publicity, Privacy, and Permanence of Information

The thermodynamics of computation is well understood for computing engines (rdquoBrownian computersrdquo) that are ideal in the sense that they can make forward and backward steps along the intended computation path, but not transitions to unrelated states. The thermodynamics of error-prone computations and error-correcting mechanisms is less well understood. We explore the speed-error-dissipation tradeoff for a family of hypothetical coupled chemical reaction schemes loosely patterned on RNA and DNA polymerases, which suffer errors at some intrinsic hardware rate and, in the case of DNA polymerases, use proofreading - cyclic dissipative reaction path - to correct most of the errors initially introduced. Even simple non-proofreading systems exhibit nontrivial features, for example a regime where the copying process is pulled slowly forward, against a backward external driving force, by the entropy of incorporated errors.

Thermodynamics of error correction: speed-error-dissipation tradeoff in copying

PROBLEM TO BE SOLVED: To prevent forgery of a record by periodically receiving a challenge from an approval source by a camera or a recording device. SOLUTION: Unpredictable digital signal and challenge are periodically and simultaneously communicated by the approval source 10. These are received and stored by an approval challenge repository 20. Simultaneously, these are also received by a video camera assembly 25, and video signal 50 is digitalized by a digitalizer 55 and is stored in a large capacity storage medium 60 for the purpose of retrieval later on. Then, this output of the means 55 is also supplied to a digester 65, and is digested by using a hash function, so as to be transmitted via a transmitting means 70 to an approval digest repository 75, where the digested digital signal is stored together with its receiving time and other identification information. Consequently, when a length between recording time and certification time is shortened, a forger is asked for a large amt. of information, and hence simulation of recording the challenge in real time cannot be performed in such a brief time. COPYRIGHT: (C)1998,JPO

Device and method for making authenticatable digital record

The unbounded complexity exhibited by homogeneous media such as cellular automata is ordinarily quite unstable with respect to noise, with an arbitrarily small generic probabilistic perturbation causing the medium instead to relax to a unique, finitely complicated state independent of the initial conditions. We survey recent results on how irreversibility and spatial anisotropy allow unboundedly complex behavior to persist in spite of such noise.

Charles H. Bennett

Papers

Improvements to time bracketed authentication

Publicity, Privacy, and Permanence of Information

Thermodynamics of error correction: speed-error-dissipation tradeoff in copying

Device and method for making authenticatable digital record

Dissipation, anisotropy, and the stabilization of computationally complex states of homogeneous media