Conductance fluctuations due to variable-range hopping in 1D metal-oxide-semiconductor field-effect transistors are investigated in the presence of a magnetic field. With an increase in magnetic field, the Zeeman effect shifts the fluctuations to lower or higher chemical potentials. These shifts reflect the relative populations and occurrence of hopping from singly and doubly occupied sites. Combined with density-of-states measurements, they can provide an estimate of the intrasite Coulomb repulsion in 1D metal-oxide-semiconductor field-effect transistors. The orbital effect on conductance fluctuations is also discussed.

• Received 19 May 1986

DOI:https://doi.org/10.1103/PhysRevLett.57.1615