Gottfried Landwehr – författare

High magnetic fields have been an important tool in semiconductor physics for a long time. The area has been growing very rapidly since quantum effects in silicon field-effect transistors have become of practical interest. Since the discovery of the quantum Hall effect by Klaus von Klitzing in 1980, this subject has grown exponentially. The book contains 42 invited papers and 37 contributed papers which were presented at the 7th of the traditional Würzburg conferences. For the area of high magnetic fields applied in semiconductor physics recent results are discussed, and the state-of-the-art is reviewed. More than 50% of the papers concern two-dimensional electronic systems. Other subjects of current interest are magneto-optics and magneto transport in three-dimensional semiconductors. Special attention has been paid to the rapidly growing field of semimagnetic semiconductors.

This volume contains contributions presented at the International Conference "The Application of High Magnetic Fields in Semiconductor Physics", which was held at the University of Wiirzburg from August 22 to 26, 1988. In the tradition of previous Wiirzburg meetings on the subject - the first conference was held in 1972 - only invited papers were presented orally. All 42 lecturers were asked to review their subject to some extent so that this book gives a good overview of the present state of the respective topic. A look at the contents shows that the subjects which have been treated at previous conferences have not lost their relevance. On the contrary, the application of high magnetic fields to semiconductors has grown substantially during the recent past. For the elucidation of the electronic band structure of semicon­ ductors high magnetic fields are still an indispensable tool. The investigation of two-dimensional electronic systems especially is frequently connected with the use of high magnetic fields. The reason for this is that a high B-field adds angular momentum quantization to the boundary quantization present in het­ erostructures and superlattices. A glance at the contributions shows that the majority deal with 2D properties. Special emphasis was on the integral and fractional quantum Hall effect. Very recent results related to the observation of a fraction with an even denbminator were presented. It became obvious that the polarization of the different fractional Landau levels is more complicated than originally anticipated.

High magnetic fields have, for a long time, been animportant tool in the investigation of the electronicstructure of semiconductors. In recent yearsstudies ofheterostructures and superlattices have predominated, andthis emphasis is reflected in these proceedings. Thecontributions concentrate on experiments using transport andoptical methods, but recent theoretical developments arealso covered. Special attention is paid to the quantum Halleffect, including the problem of edge currents, theinfluence of contacts, and Wigner condensation in thefractional quantum Hall effect regime.The 27 invited contributions by renowned expertsprovide anexcellent survey of the field that is complemented bynumerous contributed papers.

This volume contains contributions presented at the 12th International Conference on High Magnetic Fields in Semiconductor Physics. In order to give an overview, 37 lecturers not only reviewed the latest results in their field, but also gave a general introduction. The rapid development of semiconductor physics and technology during the last few years has resulted in an extensive application of high magnetic fields in both fundamental and applied research; more than 160 contributed papers were presented as posters.Sixteen years after its discovery, the quantum Hall effect (QHE) is still a subject of high activity. Many new results on the fractional QHE were presented; in addition to 6 invited papers, there were 43 contributions. Another field of high activity is magneto-optics, and 49 posters were presented. Magnetotransport also turned out to be of high interest, and magnetic semiconductors played a prominent role at the conference, too.Without doubt, the availability of superconducting magnets in most laboratories contributed to the growth of semiconductor physics in high magnetic fields. Because not all experiments can be performed in fields up to 10 or 15 teslas, high magnetic field laboratories offering larger fields are indispensable. There were reports from four laboratories on present work going on at these installations.