Heterostructures in Semiconductors

Abstract

Good morning, Gentlemen!On behalf of the Nobel Foundation, I should like to welcome you to the Nobel Symposium on "Heterostructures inSemiconductors". It gives me great pleasure to see so many colleagues and old friends from all over the world in theaudience and, in particular, to bid welcome to our Nobel laureates, Prof. Esaki and Prof. von Klitzing.In front of a different audience I would now commend the scientific and technological importance of heterostructures insemiconductors and emphatically emphasise that heterostructures, as an important contribution to microelectronics and,hence, information technology, have changed societies all over the world. I would also mention that information technologyis one of the most important global key industries which covers a wide field of important areas each of which bears its owncharacter. Ever since the invention of the transistor, we have witnessed a fantastic growth in semiconductor technology,leading to more complex functions and higher densities of devices. This development would hardly be possible without anincreasing understanding of semiconductor materials and new concepts in material growth techniques which allow thefabrication of previously unknown semiconductor structures.But here and today I will not do it because it would mean to carry coals to Newcastle. I will therefore not remind youthat heterostructures were already suggested and discussed in detail a long time before proper technologies were availablefor the fabrication of such structures. Now, heterostructures are a foundation in science and part of our everyday life.Though this is certainly true, it is nevertheless fair to say that not all properties of heterostructures are yet understoodand that further technologies have to be developed before a still better understanding is obtained. The organisers thereforehope that this symposium will contribute not only to improving our understanding of heterostructures but also to openingnew perspectives for future applications.We are most grateful that you agreed with the special format of the symposium which clearly does not follow conven-tional conferences. Allow me to call your special attention once again to two main differences: The presentations are notreview papers praising already achieved break-throughs but introductions to a list of open questions and issues for whichour understanding is still unsatisfactory. To give such presentations requires courage and scientific integrity. I would like tothank all speakers now already for their willingness to cope with such a difficult task.We have allocated at least 50 minutes for discussion after each presentation not only for discussing the paper as such but,if possible, to find answers to the open questions. If one or several participants in the audience during the discussion thinkthey can contribute to improving our understanding of heterostructures, they are invited to write their ideas up and, if thereferees agree, we are more than happy to publish these ideas in the proceedings.We admit that the program is rather demanding. For that reason, we plan to have a break on Thursday afternoon byfirst going to Denmark and touring the Hamlet castle of Kronborg. We then sail back to Sweden and will be hosted by theKrapperup castle where we will have a candle-light dinner and thereafter a baroque music concert featuring the ConcertoCopenhagen. All participants, observers, and accompanying spouses are invited and we hope you will all enjoy the excur-sion.The local organising committee acknowledges with pleasure the financial and all other support received from the NobelFoundation and the Nobel Institute of Physics as well as the initial initiative taken by the chairman of the Nobel Com-mittee for Physics, Prof. Nordling, who was the first to suggest this Nobel Symposium on "Heterostructures in Semicon-ductors". Special thanks also to the members of the program committee who have been of inestimable value in puttingtogether the program and suggesting speakers and potential participants.Moreover, I should like to thank Mrs. Medborg, Dr. Olajos, Dr. Mats Kleverman and in particular Dr. Ask who tookcare of all time-consuming negotiations and details. Without their help, the Symposium would not be what it is.The Nobel Foundation, the Nobel Committee for Physics, the Nobel Institute of Physics and the local organisers hopethat you will enjoy the Symposium and I promise you, we will all do our best to make your stay as pleasant as possible andthis Symposium a success. Once again welcome to Arild and the Symposium!