Hopping Conductivity in InSb based 2D Electronic Systems at High Magnetic Fields
Abstract
InSb/InAlSb based 2D electronic systems provide a unique window for the study of hopping conductivity at high magnetic fields. With such a small effective mass (m=0.014m_e) and large Lande g factor (g_InSb=100 g_GaAs), the cyclotron and spin gaps are enormous (hbar ωc = 90K/Tesla and g μ B = 30K/Tesla). This translates into deep wide gaps in the density of states (DOS) where hopping based conductivity dominates at all but the highest temperatures. Within these gaps, we have observed ρ_xx∝ exp-(T_0/T) ^1/2 suggestive of Coulomb gap or Ono variable range hopping and have measured T0 as a function of filling factor (ν) around ν =1, 2 , and 3. We will discuss these measurements and the resultant picture of the DOS which emerges from our fit based on Ono variable hopping.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1998
- Bibcode:
- 1998APS..MAR.G3312M