Magnetotransport in low-density p-Si/SiGe heterostructures : from metal through hopping insulator to Wigner glass.
We study dc and ac transport in low-density p-Si/SiGe heterostructures at low temperatures and in a broad domain of magnetic fields up to 18 T. Complex ac conductance is determined from simultaneous measurement of velocity and attenuation of a surface acoustic wave propagating in close vicinity of the two-dimensional hole layer. The observed behavior of dc and ac conductances is interpreted as an evolution from metallic conductance at B=0 through hopping between localized states in intermediate magnetic fields (close to the plateau of the integer quantum Hall effect corresponding to the Landau-level filling factor {nu}=1) to formation of the Wigner glass in the extreme quantum limit (B {ge} 14, T {le} 0.8 K).
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); National Science Foundation (NSF); Russian Academy of Science; Norwegian Research Cpuncil
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 1004865
- Report Number(s):
- ANL/MSD/JA-68895; TRN: US201104%%1148
- Journal Information:
- Phys. Rev. B, Vol. 77, Issue Feb. 2008
- Country of Publication:
- United States
- Language:
- ENGLISH
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