Handbook on the Physics and Chemistry of Rare Earths (eBook)

Jean-Claude G. Bunzli, Vitalij K. Pecharsky (Herausgeber)

eBook Download: PDF | EPUB

2014 | 1. Auflage
168 Seiten
Elsevier Science (Verlag)
978-0-444-63264-7 (ISBN)

Infos

The Handbook on the Physics and Chemistry of Rare Earths is a continuous series of books covering all aspects of rare earth science - chemistry, life sciences, materials science, and physics. The main emphasis of the Handbook is on rare earth elements [Sc, Y and the lanthanides (La through Lu)] but whenever relevant, information is also included on the closely related actinide elements. The individual chapters are comprehensive, broad, up-to-date critical reviews written by highly experienced invited experts. The series, which was started in 1978 by Professor Karl A. Gschneidner Jr., combines and integrates both the fundamentals and applications of these elements and now publishes two volumes a year. - Individual chapters are comprehensive, broad, critical reviews - Contributions are written by highly experienced, invited experts - Up-to-date overviews of developments in the field

Inhalt

Front Cover 1
Fundamentals of Learning and Memory 4
Copyright Page 5
Table of Contents 6
PREFACE 12
PREFACE TO THE FIRST EDITION 16
PART 1: INTRODUCTION 19
Chapter 1. What is learning? A word definition and some examples 21
A Verbal Definition of Learning 23
Examples of Learning 26
Summary 42
Chapter 2. Classical and instrumental conditioning 44
Operant and respondent conditioning 45
Classical conditioning 45
Selected examples of instrumental conditioning 60
summary 69
Chapter 3. Learning tasks: Some similarities and differences 72
Is paired-associate learning related to either classical or instrumental conditioning? 74
Classical and instrumental conditioning compared 79
Similarities among paired-associate learning, classical conditioning, and instrumental conditioning 91
conclusion 102
summary 102
Chapter 4. Biological limits 104
The "interchangeable-parts" conception of learning 105
The continuum of preparedness 107
Bait shyness: taste aversion 112
Species-specific defense reactions 119
Instinctive drift 121
Imprinting 122
Implications for general learning theory 136
summary 137
PART 2: ACQUISITION 140
Chapter 5. The role of contiguity in learning 144
The concept of contiguity 145
What are stimuli, responses, and associations? 148
The search for noncontiguous learning 155
Contiguity without learning 162
conclusion 164
summary 164
Chapter 6. The role of practice in learning 167
Introduction 168
Learning curves 171
Hull's system: A theory of gradual growth 180
All-or-none theory 186
Patterns of practice 196
Levels of processing 201
conclusion 203
summary 204
Chapter 7. Reinforcement: Facts and theory 207
Operational and theoretical definitions 208
Parameters of reinforcement 209
Secondary reinforcement 231
Theories of reinforcement 239
conclusion 244
summary 245
PART 3: TRANSFER 250
Chapter 8. Generalization and discrimination 252
Generalization 253
Discrimination and stimulus control 262
Discrimination processes in humans 274
Response differentiation 284
summary 286
Chapter 9. Transfer of training 290
Transfer designs: specific and nonspecific transfer 292
Specific transfer: similarity effects 296
The stage analysis of transfer of training 300
Generalization and transfer of training 304
Mediation paradigms and transfer of training 305
Part-whole transfer in free recall 307
Negative transfer in problem solving 309
Transfer effects and animals 309
summary 310
PART 4: RETENTION 314
Chapter 10. Interference and memory 317
Proactive inhibition 318
Retroactive inhibition 321
Decay versus interference 323
Variables affecting PI and RI 324
The generality of interference effects 327
The two-factor theory of forgetting 328
Challenges to unlearning 336
A further challenge: accessibility versus unavailability 338
Reducing interference effects 339
summary 342
Chapter 11. Information processing and memory 346
The components of memory: encoding, storage, and retrieval 347
Separate-storage models 351
Sensory memory, short-term store, long-term store 359
Additional models: more and less 368
Levels of processing 372
A continuum of memory models 374
summary 375
Chapter 12. Issues in memory 378
Introduction 379
Short-term memory versus long-term memory 380
Recognition versus recall 394
Episodic versus semantic memory 399
Animal memory versus human memory 401
Contextual cues and state-dependent memory 408
summary 409
Chapter 13. Structure and organization in memory 413
Introduction 414
Word association 416
Chunking and rewriting: 7±2 419
Clustering in recall 422
Subjective organization 425
Lexical memory 428
Stimulus selection: animals and humans 436
Mental images 440
Mnemonics 445
Issues in organization 448
summary 449
PART 5: COGNITIVE PROCESSES 454
Chapter 14. Concepts and problems 458
What is concept formation? 459
Simple concept formation 460
Complex concept learning: rules versus prototypes 470
Animals and concepts 476
Problem solving 477
Gestalt interpretations 478
Three modern ideas: subgoals, heuristics, strategies 481
Transfer in problem solving 486
Planning and problem solving 488
summary 489
Chapter 15. Language 491
The importance of language 492
Language development 493
Words 496
Sentences 498
Prose 510
Apes and language 519
summary 521
PART 6: EXTENSIONS AND APPLICATIONS 524
Chapter 16. The physical basis of learning 527
Rationale 528
Techniques 529
The physical brain 530
The electrical brain 534
The chemical brain 539
The synapse: chemical and electrical interaction 543
summary 545
Chapter 17. Behavior modification 548
Introduction 549
Positive reinforcement 552
Negative reinforcement 560
Extinction techniques 561
Punishment techniques 565
Cognitive behavior modification 566
Mixed methods 571
The problem of generalization 575
summary 576
REFERENCES 580
NAME INDEX 641
SUBJECT INDEX 651

Textauszug

Chapter 267

Rare Earth-Doped Crystals for Quantum Information Processing

Philippe Goldner1; Alban Ferrier1,2; Olivier Guillot-Noël1,*    1 Institut de Recherche de Chimie Paris, CNRS-Chimie, ParisTech, Paris, France
2 Sorbonne Universités, UPMC Univ Paris 06, Paris, France
* In memoriam

Graphical Abstract

Quantum information processing (QIP) uses superposition states of photons or atoms to process, store, and transmit data in ways impossible to reach with classical systems. Rare earth-doped crystals have recently emerged as promising systems for these applications, mainly because they exhibit very narrow optical transitions at low temperature. This allows to use these materials as quantum light-matter interfaces or to optically control their quantum states. In this chapter, after a brief introduction to QIP and coherent light-matter interactions, specific spectroscopic properties of rare earth-doped crystals are reviewed. This includes hyperfine structures, coherent properties of optical and hyperfine transitions, as well as techniques to extend coherence lifetimes. Two applications are then discussed in more details: quantum memories and computers. In these last parts, concepts and protocols are presented as well as a few representative experimental examples.

Keywords

Quantum information processing

Single crystals

Coherence

Hyperfine levels

Photon echo

Spectral hole burning

Acronyms and abbreviations

AFC atomic frequency comb

AJ hyperfine coupling constant

CF crystal field

CNOT control not gate

CRIB controlled reversible inhomogeneous broadening

DD dynamical decoupling

EIT electromagnetically induced transparency

EPR electron paramagnetic resonance

f oscillator strength

FID free-induction decay

GEM gradient echo memory

gJ Landé’s factor

HYPER hybrid photon-echo rephasing

I nuclear spin quantum number

J total angular momentum quantum number

L orbital angular momentum quantum number

NMR nuclear magnetic resonance

P quadrupolar coupling constant

QIP quantum information processing

QML quantum memories for light

rf radiofrequency

RHS Raman heterodyne scattering

ROSE revival of silenced echo

S electron spin quantum number

sech hyperbolic secant function

SHB spectral hole burning

T1 population lifetime

T2 coherence lifetime

T2hf hyperfine coherence lifetime

TM phase memory time

TLS two-level system

ZEFOZ zero first-order Zeeman shift

α absorption coefficient

η asymmetry coupling constant

γn nuclear gyromagnetic factor

Γeff effective homogeneous linewidth

Γh homogeneous linewidth

Γinh inhomogeneous linewidth

μB Bohr magneton

Ω Rabi frequency (rad s−1)

1 Introduction

Information in digital form is at the heart of nowadays societies, playing a major role in world-scale organizations down to many individual daily activities. Although technology made extraordinary progresses in terms of communication speed and capacity, data storage, or processing power, most of the fundamental concepts of information science were established in the beginning of the twentieth century. In 1984, a quantum algorithm was discovered by Bennett and Brassard for encrypted data exchange (Bennett and Brassard, 1984) and in 1985, Deutsch pioneered quantum computing theory (Deutsch, 1985). This was the start of quantum information processing (QIP), which is currently a major research topic in physics, computer science, mathematics, and material science. Quantum information is a new paradigm, where the classical bits, which can take only discrete values, are replaced by quantum bits, called qubits, which can assume any superposition state. This fundamentally new resource allows data processing, storage, and communication in ways impossible to achieve with classical systems (Kimble, 2008; Nielsen and Chuang, 2000; Stolze and Suter, 2008).

QIP is however very demanding on physical systems and its development has triggered important advances in quantum system control and design. In turn, QIP theory has emerged as a unified way to describe the behavior of these systems, independently of the details of their nature, structure, or interactions. QIP uses superposition states, which exist for a significant duration only in isolated systems. Interactions with a fluctuating environment, with many degrees of freedom, destroy them. Examples of quantum systems suitable for QIP are photons (Gisin and Thew, 2007; Kok et al., 2007) and nuclear spins (Chuang et al., 1998; Morton et al., 2008), which can have very low interactions with surrounding electromagnetic fields and atoms. QIP is also investigated in many other systems (Ladd et al., 2010; Lvovsky et al., 2009) such as trapped ions (Blatt and Roos, 2012), superconductors (Clarke and Wilhelm, 2008), electronic and nuclear spins in insulators and semiconductors (Hanson et al., 2007; Wrachtrup and Jelezko, 2006), and ultracold atoms (Bloch et al., 2012; Chanelière et al., 2005). As light is an excellent carrier of quantum information, as it is of classical one, there is also a need to interface it to material systems to store and process information (Northup and Blatt, 2014). Moreover, progress in lasers has also set them as efficient devices for controlling efficiently and accurately quantum systems. In these respects, rare earth (R)-doped crystals have very favorable spectroscopic properties among solid-state systems. The main one is to exhibit extremely narrow optical transitions, equivalent to long-lived superposition states, at cryogenic temperatures (Macfarlane, 2002). Depending on the R ions considered, these transitions span the entire visible and infrared range, including the telecom window at 1.5 μm. Moreover, many R ions have isotopes with nonzero nuclear spins, which can be therefore optically controlled or interfaced with photonic qubits. Finally, R-doped crystals are generally very robust, photostable materials, which can be readily cooled down to liquid helium temperatures in closed cycle cryostats. Their synthesis and spectroscopy have been widely developed for applications in photoluminescence, lasers, scintillation, etc. In addition, these materials are studied for classical information or signal processing, which shares some requirements and schemes with QIP applications (Le Gouët et al., 2006; Li et al., 2008; Thorpe et al., 2011).

In this chapter, we review the applications of R-doped crystals to two specific QIP applications: optical quantum memories and quantum computing. After a brief introduction to QIP, we describe coherent light-atom interactions, which allow creating and controlling atomic quantum states. The spectroscopic properties of R-doped crystals are discussed afterward, with a focus on the specific features used in QIP. Finally, the concepts and studies related to quantum memories and computing are presented. In the two last sections, we chose to emphasize a few representative experiments, underlining important points, rather than to give extensive lists of results. As this field is relatively new to the rare-earth community, we felt that this approach could be more useful for the reader.

2 Quantum Information Processing

2.1 Qubits and Gates

The reader is referred to Nielsen and Chuang (2000) or Stolze and Suter (2008) for a detailed presentation of QIP. In the following, we only review the basic concepts of the field. The qubit, or quantum bit, is the elementary unit of information in QIP. It is the equivalent of the bit in classical computing and communication. The bit can take two values, 0 or 1, and is implemented as different states...

Produkt-Details

• Erscheint lt. Verlag: 27.11.2014
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Chemie ► Anorganische Chemie
• Themenwelt: Naturwissenschaften ► Physik / Astronomie ► Elektrodynamik
• Themenwelt: Technik
• ISBN-10: 0-444-63264-6 / 0444632646
• ISBN-13: 978-0-444-63264-7 / 9780444632647