Ebook: Nanometer Scale Science and Technology

The many wonders of nanophysics were first anticipated by Richard Feynman in a speech he gave in late 1959, subsequently published under the title “There's Plenty of Room at the Bottom”. Feynman was able to grasp the new physics at the atomic or nanometer scale, which has arrived at the verge of fruition today in many areas from information technology and medicine to manufacturing and the environment. Nanophysics is not synonimous with nanotechnology, but it depends heavily on the nanotechnologies required to produce, to investigate and to manipulate single atoms and molecules and other nanostructures. Nanophysics, however, goes one step further than nanotechnology because it also requires a profound understanding of the magical world on the length scales where the smallest of human-made devices and the large molecules of living systems meet.

The CXLIV Course of the Enrico Fermi School, held in Varenna at the beautifully renovated Villa Monastero from June 27 to July 7, 2000, focuses on “Nanometer Scale Science and Technology”. This is one of the most rapidly expanding research fields and it is considered one of the most important issues in forming future societies. Nanoscience and nanotechnology are at the interface between physics, chemistry, engineering and, most importantly, biology. The most fundamental processes of living matter occur on the nanometer scale. Micro-electrical mechanical systems are approaching the dimensions of biological cells, opening up the possibility of connecting machines to individual cells. This Course, the first in this field at the Enrico Fermi School, successfully attempted to convey to students the flavour of “the magic of the small”. In physics it is the domain of the interface between condensed matter and atoms and molecules. Given the highly interdisciplinary character of this advanced research, we have been forced to select a few topics among a large variety. The Course was based on local probes (STM, AFM, SNOM) and related supreme technological achievements. These topics were extensively covered in a set of lectures and seminars, mainly devoted to instrumentation aspects. From a more fundamental point of view it also covers advanced subjects such as clusters, nanocontacts, photonic band gap materials, atom manipulation by light, atom optics with Bose-Einstein condensates and quantum computing. The information industry has been driving the field of nanotechnology, whose top issues are tolerance, interfaces, intensities and peripherals. Tolerance means that true nanoscale devices should be designed to assure operation even if their dimensions on an energy scale are spread considerably. Intensities describe the fact that even though extensive quantities such as length, number of particles and currents become small, intensities remain large or become even larger. Power densities, not light intensity and electric fields may become the limiting values. Peripherals finally address the fact that nanoscale objects are hard to interface to the macroworld. One example, discussed at this School, are nanotubes. Currently, the problem of how to make electrical contacts is one of the most prominent open questions. One consequence of these four issues is that nano-objects and nanodevices should have an optimal size.

One impressive fact of this Course was that all leading researchers were leaving their original discipline and have started to work at the interfaces of physics, chemistry, biology and engineering. The lectures addressed both fundamental subjects as well as instrumental issues. A fascinating overview of the basics of quantum computing was given in four lectures. Optical properties of nanoscale objects were covered extensively, and in one seminar it was concisely shown how periodic arrays of these particles lead to photonic band gap materials. Key examples of the fabrication of nanostructures were given. Electrical properties are some of the most sought after capabilities in the microworld: ballistic magnetoresistance, nanoscale electronics and nanotubes were some of the examples presented. Two sets of lectures were devoted to showing how to bridge physics and chemistry to biology, leading to the final lectures on the nanoscience of living matter.

All through the lectures it was very clear that nanotechnology would be the future of further technological development, but that it is also a multidisciplinary technology that more than ever requires basic scientific developments for its advancement. It could be said that nanotechnology and nanoscience, the new scientific developments on the nanoscale, are simply inseparable. Also future developments as well as those of the present, necessitate a close collaboration of physicists, chemists, biologists and mathematicians.

In the discussions it was also pointed out that developments in nanotechnology in the near future will be based on the CMOS techniques that so successfully have been fuelling the micro- and submicron technology. Nanodevices will have to be compatible with the existing CMOS technology, otherwise it will be virtually impossible to introduce them into today's markets. This seems to be the opinion of the more application-oriented participants. However, there were others who think that we should learn to “imitate” Nature and its self-replicating mechanism in order to create not only memory but also operating and functional memories. The attitude of nanotechnology so far has been to reduce the size of chips and devices, which have permitted an increase in memory and compactness, but this is not enough if we really want to open up new avenues for the future. The ideas that will constitute a break-through are still to come.

In addition to the lectures and seminars, a Round Table was organized by N. García, following the opening talks of H. Rohrer who brought to the minds of all participants that science and technology cannot be discussed ignoring ethical and social consequences. Lively discussions among the participants deepened the awareness of the problem.

The success of this Course on Nanometer Scale Science and Technology was made possible firstly by all the participants, speakers, young students and senior observers, and secondly by the cooperation of many persons and institutions. We wish to thank all lecturers to whom the largest part of the credit must be given and the numerous students, from seventeen different countries all over the world, who interacted constantly and very intensively. A special thought of gratitude is due to Prof. G. F. Bassani, the President of the Italian Physical Society, who has supported our initiative with enthusiasm and knowledge from the early stages of application to the very end of the Course. Special thanks are due to Dr. M. Labardi for his dedicated work as secretary of the Course. We wish to thank Dr. I. Vodyanoy of the Office of Naval Research who followed the entire Course and contributed with lively scientific discussions as well as with a special seminar on “Funding from the US: ONRIFO International Program”. Thanks also to Dr. R. Compañó and Dr. N. Deliyanakis of the European Commission who paid a short but intense visit to our school and brought the news about the great efforts that the European Commission is making in the field of nanotechnology. B. Alzani and C. Vasini from the staff of the Italian Physical Society were marvellous in solving the logistic problems, on which the directors had no influence. R. Brigatti, F. Sabadini and S. Reichard efficiently and cheerfully helped in a smooth running of the Course. Our thanks to all of them.

We acknowledge the generous support by the Italian Physical Society (SIF), the European Commission through its Euroconferences and Euroschools programme and the TMR Network NanoSNOM, the European Office of Naval Research (ONRIFO), the UNESCO, the Swiss National Science Foundation and the Gruppo Nazionale di Struttura della Materia of the Italian National Research Council (GNSM-CNR).

M. Allegrini, N. García and O. Marti

1. The magic

2. The legacy

3. The nanometer scale

4. Nanotechnology, the continuation of a development

5. The new nanotechnology

6. Back to the future of mechanics

7. The prospects

1. Introduction

2. Highlights of STM studies

3. Introduction to AFM: contact mode

4. Noncontact AFM

5. AFM-related experiments — Nanomechanics

6. Conclusions

1. Introduction

2. Some theoretical foundations

3. Instrumentation

4. Applications to polymers

5. Application to semiconductors and to devices

6. Comparison to confocal microscopy

7. Outlook

1. Introduction

2. Resolution in optical microscopy

3. Basics of SNOM

4. Aperture SNOM

5. Image interpretation

6. Apertureless SNOM with passive probes

7. Apertureless SNOM with active probes

8. Scanning probe techniques and nano-optics

9. Conclusions

1. Introduction

2. Basic notions in quantum information

3. Quantum computation

4. Decoherence and error correction

5. Physical implementations

6. Conclusions

Part I. Some optical properties of nanoparticles and cluster-matter

Part II. Some electronic properties of nanoscale interfaces

Part III. Chemical reactions and phase transitions of yttrium clusters

1. Introduction

2. Methods

3. Representative examples

4. Conclusions

1. Why molecules?

2. Molecular imaging and chemical identification

3. Spectroscopic imaging and molecular contrast in STM

4. Molecular systems on semiconductor surfaces

5. Molecular electronic devices

1. Introduction

2. AFM: hard tips on soft cells

3. Force spectroscopy: giving proteins a hard time

4. Photonic Force Microscopy (PFM): getting thermally excited

5. STM and biology: a possible connection?

1. Introduction

2. Laser cooling

3. Optical lattices

4. Atom lithography

1. Introduction

2. Theoretical studies of photonic crystals

3. Acoustic and elastic waves

4. Conclusions

1. Introduction

2. Band structure of carbon nanotubes

3. Electric transport in MWNTs: A brief review

4. Hall-effect and thermopower in assembled nanotubes

5. Electrical transport of single MWNTs

6. Discussion of the main issues

1. Introduction

2. The Millipede concept

3. Thermomechanical AFM data storage

4. Array design, technology, fabrication

5. Array characterization

6. First write/read results with the 32 × 32 array chip

7. Conclusion and outlook

1. Introduction

2. Theory

3. Experiments on ballistic magnetoresistance

4. Magnetoresistance manipulation experiments

5. Summary

1. Introduction

2. Nanometer-scale structures fabrication and conductance measurements

3. Concluding remarks

1. The background

2. The reference point: CMOS

3. Trends

4. Outlook

1. Introduction

2. Femtosecond decay time measurements

3. Applications of nanoparticle arrays as optical thin film filters

4. Application of nanoparticles for optical storage media

5. Application of MNPs for fluorescence enhancement in biochemical sensorics

1. Introduction

2. Spectral properties of emitted thermal near fields

3. Radiative heat transfer at nanometric distances

4. Spatial coherence of thermal near fields

5. Conclusion

1. Introduction

2. Time-resolved diffraction experiments

3. Time-resolved interference experiments

4. Discussion

1. Introduction

2. Nanoparticle resonances

3. Optical forces

1. Introduction

2. Model

3. Modulation techniques

4. Near-field discrimination

5. Results

6. Conclusions