摘要:

Time-reversal invariance is a very powerful concept in classical and quantum mechanics. However, simple experimental evidence of this concept is difficult to obtain. In the field of acoustic waves, time-reversal experiments may be achieved much more simply by using time-reversal mirrors made of large ultrasonic piezoelectric transducer arrays.

ISSN:0010-7514    

DOI:10.1080/00107519608230338

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

This article reviews some of the more important applications of semiconductor quantum wells in optoelectronic devices. The use of quantum wells has been beneficial for three main research directions. Firstly, improved performance has been obtained in devices such as laser diodes, light-emitting diodes and solar cells. Secondly, new devices with operating principles related to the two-dimensional quantum confinement have been invented; examples are the quantum-confined Stark effect modulators and logic gates, and intersubband infrared detectors. Finally, quantum effects have been studied in new systems, and elusive fundamental phenomena such as Bloch oscillations have been observed for the first time.

ISSN:0010-7514    

DOI:10.1080/00107519608230339

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The quantum Hall effect is the precise quantization, in units e2/h, of the Hall conductance of a system of charge carriers constrained to move in a plane, with a perpendicular magnetic field. It was discovered experimentally by von Klitzing et al. in 1980, and successful theories were put forward soon after. One approach to the theory involves concepts of algebraic topology; the Hall conductance is expressed as a topological invariant called the Chern class. This article is an informal review of the topological theory of the integer quantum Hall effect, including a non-technical introduction to the mathematical concepts involved.

ISSN:0010-7514    

DOI:10.1080/00107519608230340

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The genetic algorithm is present as an artificial intelligence search method particularly suitable for solving problems in the physical sciences. The details of the algorithm are given, and the method illustrated by way of application to the estimation of the ground-state energy of the spin glass and the registration of magnetic resonance images. The theory behind the method is also discussed.

ISSN:0010-7514    

DOI:10.1080/00107519608230341

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0010-7514    

DOI:10.1080/00107519608230342

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0010-7514    

DOI:10.1080/00107519608230343

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Advances in Actuators. In the series Sensors. Edited by A. P. Dorey and J. H. Moore. 1995, £65.00 (hbk), pp. viii + 221. IOP, ISBN 0 7503 0291 7. Scope: multi-author review. Level: postgraduate and specialist.

ISSN:0010-7514    

DOI:10.1080/00107519608230344

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0010-7514    

DOI:10.1080/00107519608230345

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor