Standard Article

Cyclotron Resonance

  1. J. Kono

Published Online: 15 OCT 2002

DOI: 10.1002/0471266965.com068

Characterization of Materials

Characterization of Materials

How to Cite

Kono, J. 2002. Cyclotron Resonance. Characterization of Materials. .

Author Information

  1. Rice University, Houston, Texas

Publication History

  1. Published Online: 15 OCT 2002

This is not the most recent version of the article. View current version (18 MAY 2012)


Cyclotron resonance (CR) is a method for measuring the effective masses of charge carriers in solids. It is by far the most direct and accurate method for providing such information. In the simplest description, the principle of the method can be stated as follows. A particle of effective mass inline image and charge inline image in a DC magnetic field inline image executes a helical motion around inline image with the cyclotron frequency inline image. If, at the same time, an AC electric field of frequency inline image is applied to the system, perpendicular to inline image, the particle will resonantly absorb energy from the AC field. Since inline image and/or ω can be continuously swept through the resonance and known to a very high degree of accuracy, inline image can be directly determined with high accuracy by inline image.

As a secondary purpose, one can also use CR to study carrier scattering phenomena in solids by examining the scattering lifetime τ (the time between collisions, also known as the collision time or the transport/momentum relaxation time), which can be found from the linewidth of CR peaks.

Although this article is mainly concerned with the simplest case of free carrier CR in bulk semiconductors, one can also study a wide variety of FIR magneto-optical phenomena with essentially the same techniques as CR. These phenomena (“derivatives” of CR) include: (a) spin-flip resonances, (b) resonances of bound carriers, (c) polaronic coupling, and (d) 1-D and 2-D magneto-plasmon excitations.

It is important to note that all the early CR studies were carried out on semiconductors, not on metals.

Many techniques can provide information on effective masses, but none can rival CR for directness and accuracy. Effective masses can be estimated from the temperature dependence of the amplitude of the galvanomagnetic effects.

The basic theory and experimental methods of cyclotron resonance are presented in this article. Basic theoretical background is presented. A detailed description is given of the actual experimentation procedures. Finally, typical data analysis procedures are presented.


  • cyclotron resonance (CR);
  • quantum mechanics;
  • practical aspects;
  • far infrared radiation (FIR);
  • fourier transform;
  • magneto-spectroscopy;
  • resonance spectroscopy;
  • data analysis;
  • initial interpretation;
  • sample preparation;
  • problems