There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

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

Current research into semiconductor clusters is focused on the properties of quantum dots-fragments of semiconductor consisting of hundreds to many thousands of atoms-with the bulk bonding geometry and with surface states eliminated by enclosure in a material that has a larger band gap. Quantum dots exhibit strongly size-dependent optical and electrical properties. The ability to join the dots into complex assemblies creates many opportunities for scientific discovery.

Semiconductor Clusters, Nanocrystals, and Quantum Dots

Recent years have witnessed many breakthroughs in research on graphene (the first two-dimensional atomic crystal) as well as a significant advance in the mass production of this material. This one-atom-thick fabric of carbon uniquely combines extreme mechanical strength, exceptionally high electronic and thermal conductivities, impermeability to gases, as well as many other supreme properties, all of which make it highly attractive for numerous applications. Here we review recent progress in graphene research and in the development of production methods, and critically analyse the feasibility of various graphene applications.

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A roadmap for graphene

The articles in this special section focus on optical interconnects. These papers present the most recent developments in this field with extensiveness and depth, while ensuring the inclusion of the highest quality work. Large-scale data centers and high-performance computers (HPC) are becoming increasingly limited by the capacity of interconnects due to the rapidly increasing power consumption and bandwidth demands. As a result of the continuing bandwidth scaling, optical interconnects (OI) have been implemented at ever decreasing communication distances to replace electrical interconnects. Over the past decade, core switches and routers in data centers and HPC systems have adopted fiber optics to deliver the I/O performance between racks in multi-chassis configurations. Meanwhile, the further penetration of OI into shorter distances, such as the board and chip levels, poses new challenges on photonic integrated circuits (PICs) for continued performance and cost scaling and further requires innovations in integration and packaging.

Guest Editorial Special Issue on Optical Interconnects

SiGe quantum wells where the well material has a lowest conduction band energy minimum at k=0 (the Γ point of the first Brillouin zone) are provided. Quantum well structures that satisfy this condition have “Kane-like” bands at and near k=0 which can provide physical effects useful for various device applications, especially optical modulators. In the Si 1-x Ge x material system, this condition on the band structure is satisfied for x greater than about 0.7. The quantum well barrier composition may or may not have Kane-like bands. Optical modulators including such SiGe quantum wells can be operated at temperatures other than room temperature. Such temperature control is preferred for providing optical modulators that operate in the telecommunication C band (˜1530 nm to ˜1565 nm).

Temperature-controlled optical modulator

Summary from only given. We demonstrate the operation of a link with high immunity to supply and substrate noise. A total link power penalty of only 0.12 dB/ 100 mV of receiver supply noise was observed. Link performance was unaffected by substrate noise injection from a voltage controlled oscillator (VCO). This high immunity can be attributed to the differential nature of the receiver. The effect of supply noise and crosstalk on electrically single-ended receivers has been studied. To the best of our knowledge, however, this is the first demonstration of the operation of an entire chip-to-chip optical link with modulators and electrically differential receivers quantifying the effect of supply and substrate noise.

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Optical interconnect operation with high noise immunity

Prerequisite: Chapter 2. Thus far with Schrodinger's equation, we have considered only situations where the spatial probability distribution was steady in time. In our rationalization of the time-independent Schrodinger equation, we imagined we had, for example, a steady electron beam, where the electrons had a definite energy; this beam was diffracting off some object, such as a crystal or through a pair of slits. The result was some steady diffraction pattern (at least, the probability distribution did not vary in time). We then went on to use this equation to examine some other specific problems, including potential wells, where this requirement of definite energy led to the unusual behavior that only specific, “quantized” energies were allowed. In particular, we analyzed the problem of the harmonic oscillator and found stationary states of that oscillator. On the face of it, stationary states of an oscillator (other than the trivial one of the oscillator having zero energy) make little sense given our classical experience with oscillators – a classical oscillator with energy oscillates. Clearly, we must expect quantum mechanics to model situations that are not stationary. The world about us changes, and if quantum mechanics is to be a complete theory, it must handle such changes. To understand such changes, at least for the kinds of systems where Schrodinger's equation might be expected to be valid, we need a time-dependent extension of Schrodinger's equation.

The time-dependent Schrödinger equation

We show that simple transmission line models can describe mode propagation in plasmonic waveguides. Despite different metal behavior at near-infrared compared to microwaves, our simulation results agree very well with our impedance model predictions.

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David A. B. Miller

Papers

Guest Editorial Special Issue on Optical Interconnects

Temperature-controlled optical modulator

Optical interconnect operation with high noise immunity

The time-dependent Schrödinger equation

Plasmonic Waveguides as Transmission Lines