We demonstrate substantial magnetic-field tuning of the metal-insulator transition in Ge:Sb for H < 20 kOe. From a fit to the conductivity in a series of samples at millikelvin temperatures in different fields to the critical form σ ∼ (n/nc(H) - 1)μ, we find that μ ≈ 1 independent of H, but that nc(H) increases more than 25% by H ∼ 20 kOe. Moreover, nc(H) - nc(0) ∝ H1/2, in agreement with a weak-disorder perturbative scaling approach, but in contrast to recent experimental results in Si:As.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)