Low-temperature transport in the hopping regime: Evidence for correlations due to exchange

Journal Article · Mon Sep 21 00:00:00 EDT 1992 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.69.1804· OSTI ID:7048694

Dai, P; Zhang, Y; Sarachik, M P ^[1]

---

1. Department of Physics, City College of the City University of New York, New York, New York 10031 (United States)

Activated conduction, {rho}={rho}{sub 0} exp(({ital T}{sub 0}{sup {prime}{prime}}/{ital T}){sup {ital x}}), with {ital x} equal to or close to 1 is observed for insulating Si:B at low temperatures, indicating the presence of a hard'' gap in the density of states. A magnetic field suppresses this unexpectedly strong temperature dependence, changing it to the variable-range-hopping form {rho}({ital H})={rho}{sub 0}({ital H})exp{l brace}({ital T}{sub 0}{sup {prime}}({ital H})/{ital T}){sup 1/2}{r brace} expected for a soft'' parabolic Coulomb gap. This suggests that the density of states is determined by electron correlations due to spin as well as charge.

• DOE Contract Number: FG02-84ER45153
• OSTI ID: 7048694
• Journal Information: Physical Review Letters; (United States), Journal Name: Physical Review Letters; (United States) Vol. 69:12; ISSN PRLTA; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
ALLOYS
ANGULAR MOMENTUM
BORON ADDITIONS
BORON ALLOYS
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
ENERGY GAP
ENERGY-LEVEL DENSITY
MATERIALS
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
SEMIMETALS
SILICON
SPIN
TEMPERATURE DEPENDENCE