I often consult my scientific adviser on the problems concerned with my work.

Now all the participants are in the conference hall to share opinions about their research. The Chairman of the session, who is also the Chairman of the Organizing Committee, started the meeting with an opening address.

The Opening Address

Chairman: Distinguished guests, ladies and gentlemen, dear colleagues! It is a great pleasure for me as Chairman of the Organizing Committee to welcome you to the International Conference of Young Scientists sponsored by the Russian Academy of Sciences. I would like to give a special welcome to the President of the Academy, Academician Yuri Osipov, who has found the time to attend our meeting. I express our warmest welcome to the Assistant Director of the Massachusetts Institute of Technology, Professor Charles Stucky, who has brought a large group of young scientists from the Institute, and to our honorable guest Dr. Rundle from the same Institute. I am sure you will join me in extending a particular welcome to our colleagues from other countries. We are pleased that so many outstanding young researchers from all over the world have come to attend this Conference. We would like to convey our best wishes to all the participants and guests.

Two years have passed since our last meeting in Germany. It is certainly a short time, but it has turned out to be very fruitful. There has been remarkable progress in our understanding of the problems of young researchers. The most notable achievement is the introduction of the European Contest for Young Scientists. One of the objectives is attracting more young people to careers in science, which is vital for the future of European research. The European Contest for Young Scientists is an excellent example of a concrete measure to realise this. The aim of the Contest is to bring together the best scientific talents from all over Europe and from many non-European countries and to give them an exposure to an international environment - so important in today's research - and to get a taste of science in the making. The Contest highlights the scientific achievements of young people who are interested in and committed to scientific work, and rewards them for having embarked upon their research projects.

Conceiving the idea, pursuing it with different methods and approaches, and finally arriving at the end result is the essence of a scientific project. Of course there is the thrill, there are difficulties and disappointments - but at the end: the reward of having succeeded. There is teamwork on the one hand - stimulation, brainstorming, togetherness. There is competition on the other - the drive to be among the best, to come up with something nobody else has.

All these elements are present in the Contest on an international scene. The Contest is therefore not merely a competition that marks the completion of an excellent project. The Contest contributes to fostering a lifelong interest in and commitment to fundamental questions facing our society today.

Our main goal in holding this Conference is to discuss various aspects of new approaches to ‘young’ research. The range of subjects to be considered is quite large. But it is our hope that the Conference will show the current state of things in this rapidly developing area and stimulate new ideas. Because the meeting has brought together scientists with different points of view, with different backgrounds of training and experience, we expect stimulating discussions of theoretical and experimental problems. I wish you success. Thank you.

 

E x е г с i s e. Role play. Imagine you have been invited to open a conference on problems of your science. Act out an opening address, starting from a general salutation and then giving individual salutations. You can preliminarily write down the text of your opening address and learn it.

Generally, salutations are followed by reference to the previous meeting on the subject and a brief review of the progress that has been made since then. This is how it can be done:

Three years have passed since our last meeting in Italy. It is certainly a short time, but it has turned out to be very fruitful. There has been remarkable progress in our understanding of the semiconductor device operation. The most notable achievement is the discovery of room temperature superconductivity. It has brought about improvement in structure technology and in designing new devices and materials.

This can also be done in another way:

It is only one year since we met in Sweden. It is certainly a very short period of time but the work that has been done on new materials and structures is impressive. Particularly noteworthy are the studies on superconductivity. An excellent example of a recent achievement is the design of heterostructures with superconducting layers.

Reference to recent achievements is logically followed by a statement of gaps in the knowledge that require further research efforts. It can be done like this:

- However, our knowledge of the mechanism of superconductivity still remains incomplete.

Here are other examples:

(1) - Still, there are some gaps in our understanding of these phenomena.

(2) - However, further work is necessary to make the mechanism of superconductivity clearer to us.

(3) - Nevertheless, the nature of superconductivity still remains unclear.

Concluding his short opening address, the Chairman stated the goal of the Conference, outlined its subject matter and expressed hope that the Conference will promote further work in this area. He said:

- Our main goal in holding this Conference is to discuss various aspects of new approaches to ‘young’ research. The range of subjects to be considered is quite large. But it is our hope that the Conference will show the current state of things in this rapidly developing area and stimulate new ideas. Because the meeting has brought together scientists with different points of view, with different backgrounds of training and experience, we expect stimulating discussions of theoretical and experimental problems. I wish you success. Thank you.

Here are some other examples of concluding an opening address:

(1) - Our aim in convening this Symposium is to discuss the research results obtained in the past two years. The papers to be presented cover a wide range of theoretical and experimental problems. So we have included plenty of time for discussions, and hope that they will stimulate further work. During the discussions we expect to hear contributions of the participants whose abstracts could not be accepted. We wish you every success.

(2) - This Symposium will focus on some theoretical and practical aspects of materials technology. It will summarize the research efforts made since our last meeting two years ago. Sufficient time will be allowed for discussions, so we expect original contributions of those participants, whose papers could not be included in the scientific program. It is our hope that the meeting will be a success.

 

The Chairman’s opening speech was followed by a number of welcome remarks by officials who were attending the Symposium. After that, the Chairman of the session gave the floor to the Scientific Committee Chairman, Dr. Newbury who introduced the first speaker, an honorable guest of the Conference, Dr. Rundle:

- And now I have the pleasure of introducing our first speaker, Dr. Rundle of the Massachusetts Institute of Technology. He will speak about his latest research, i.e. interband scattering in a two-dimensional electron gas. Welcome, Dr. Rundle.

 

   Rundle went up the podium and started to speak.

 

Presenting a Paper

Rundle: Thank you, Mr. Chairman. I am happy to have this opportunity to present my paper at this working group session. The purpose of this study was to understand the mechanism of intersubband scattering in two-dimensional electron gas in heterostructures. It is well known that some interesting research has been done in this field in recent years. Yet, it is not clear why interband scattering rate does not increase with temperature. So the aim of this work was to find an explanation for the temperature-dependent intermodulation. We suggest an explanation in terms of oscillations in the Fermi level, which is confirmed by a model calculation. Now let me discuss in some detail the data we have obtained and the conclusions we have drawn.

I would like to start by showing some slides. (To the projectionist.) The first slide,
please. Here we see the intermodulation as a function of temperature. The data have
been multiplied by a factor of 2.5 to better display the low-field region. Let's have
a look at this plot. Next slide, please. This is a Dingle plot for a sample with only
one subband occupied. I would like to stress that the amplitude of the resistance oscillations
has been corrected for temperature. Full circles are for a temperature of 4.10 Kelvin.
(To the projectionist.) Next slide, please. Could we make the picture a bit brighter?
Thank you. Here we see Dingle plots for the data when two subbands are occupied.
Full circles are for the low frequency, that is for the upper subband. The open circles
are for the high frequency, or the lower subband. Please, note the difference between
the two lines which are least-square fits to the data. I'm afraid we'll have to skip
the next two slides, because we're short of time. (To the projectionist.) Can we see
the last slide, please? This slide demonstrates the relationship between the experimental
data and the model calculations, and you can see a good agreement. This enabled us
to make the following conclusion. When a semiclassical treatment of the amplitude of
the low-field oscillations in two-dimensional  systems is extended to the case of the
two occupied subbands, the intercept of the Dingle plots depends on the intersubband scattering. In particular, in some cases the intercept depends on the intersubband fraction of scattering for most of the carriers. Experimental results agree with this theory and
show that in the heterojunction investigated approximately one-third of the scattering is intersubband. In contrast with a previous interpretation, we attribute the phenomenon to oscillations in the Fermi energy rather than to the acoustic phonons. Our explanation is supported by a model calculation. With this I would like to finish. If there are questions I'll be glad to answer them. Thank you.