Effect of a magnetic field on the critical conductivity exponent at the metal-insulator transition
Abstract
From measurements of the resistivity down to 70 mK in magnetic fields to 7.5 T of a series of just-metallic, uncompensated, p-type Si:B samples, we have established that the critical exponent which characterizes the approach of the zero-temperature conductivity to the insulating phase changes from ν=0.65+0.05-0.14 in zero field to ν=1.0+0.10-0.20 in a magnetic field of 7.5 T. This is the first clear experimental evidence for a change in universality class at the metal-insulator transition caused by the application of a magnetic field.
- Publication:
-
Physical Review Letters
- Pub Date:
- July 1991
- DOI:
- Bibcode:
- 1991PhRvL..67..136D
- Keywords:
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- 71.30.+h;
- 72.20.My;
- Metal-insulator transitions and other electronic transitions;
- Galvanomagnetic and other magnetotransport effects