Showing papers by "Myriam P. Sarachik published in 1993"
TL;DR: Measurements between 0.05 and 1 K in magnetic fields small enough to ensure linear response indicate that the Hall coefficient of Si:B diverges at the metal-insulator transition, which is similar to Ge:Sb and differs from the finite behavior claimed for Si:As and Si:P.
Abstract: Measurements between 0.05 and 1 K in magnetic fields small enough to ensure linear response (B1 T) indicate that the Hall coefficient of Si:B diverges at the metal-insulator transition. This is similar to Ge:Sb and differs from the finite behavior claimed for Si:As and Si:F. Our result may be due to strong spin-orbit effects; it is inconsistent with a recent suggestion that the Hall coefficient is finite in systems with critical conductivity exponent \ensuremath{\mu}\ensuremath{\approxeq}1/2.
16 citations
TL;DR: These measurements in Si:P constitute a clear determination of the critical conductivity exponent near the metal-insulator transition in the universality class for high magnetic field.
Abstract: The critical conductivity exponent of Si:P changes from near 1/2 in zero field to 0.86[plus minus]0.15 in a magnetic field of 8 T, consistent with the theoretical expectation of 1. According to recent theory, similar behavior found earlier in Si:B, where spin-orbit scattering is strong, corresponds to the universality class for magnetic impurities. These measurements in Si:P thus constitute a clear determination of the critical conductivity exponent near the metal-insulator transition in the universality class for high magnetic field.
10 citations
TL;DR: The positive component expected for quantum interference in the hopping regime is absent or undetectably small in all these Si-based semiconductors even in magnetic fields as small as 200 G.
Abstract: A negative magnetoconductance is found for insulating, uncompensated [ital n]-type Si:P and Si:As, uncompensated [ital p]-type Si:B, and compensated Si:P,B at temperatures between 1.6 and 4.2 K. The positive component expected for quantum interference in the hopping regime is absent or undetectably small in all these Si-based semiconductors even in magnetic fields as small as 200 G.
8 citations