Quantum interference in the n-channel of a Si: SiGe quantum well

R. S. Prasad, Trevor Thornton, A. Matsumura, J. M. Fernandez, D. Williams

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

We have grown n-channel Si:SiGe quantum wells using gas source molecular beam epitaxy. The two-dimensional electron gas confined in the strained Si quantum well is weakly disordered and displays quantum interference in the form of a pronounced, low-field negative magnetoresistance. By fitting the data to the standard theory of weak localization, in the temperature range 50 mK to 6 K, we have been able to extract the product Nvα and the electron phase coherence length Lφ. Our results give a value for the product Nvα in the range 0.6±0.12, which is close to that expected for strong intervalley scattering and is similar to values obtained in Si MOSFETs. We show a power law dependence of Lφ with temperature, i.e. Lφ∝T-p/2. For T>0.7 K the value of the exponent p/2 = 0.75 which suggests that the dominant dephasing mechanism is electron-phonon scattering as observed in Si MOSFETs. However, for lower temperatures the variation is less pronounced (p/2 = 0.15). The weaker temperature dependence may be a precursor to a saturation in the value of Lφ as has recently been observed by other groups.

Original languageEnglish (US)
Pages (from-to)1084-1088
Number of pages5
JournalSemiconductor Science and Technology
Volume10
Issue number8
DOIs
StatePublished - Aug 1995
Externally publishedYes

Fingerprint

Semiconductor quantum wells
field effect transistors
quantum wells
interference
phase coherence
products
scattering
electron gas
electrons
molecular beam epitaxy
Gas source molecular beam epitaxy
exponents
saturation
Temperature
temperature dependence
Phonon scattering
Two dimensional electron gas
Electron scattering
temperature
Magnetoresistance

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Quantum interference in the n-channel of a Si : SiGe quantum well. / Prasad, R. S.; Thornton, Trevor; Matsumura, A.; Fernandez, J. M.; Williams, D.

In: Semiconductor Science and Technology, Vol. 10, No. 8, 08.1995, p. 1084-1088.

Research output: Contribution to journalArticle

Prasad, R. S. ; Thornton, Trevor ; Matsumura, A. ; Fernandez, J. M. ; Williams, D. / Quantum interference in the n-channel of a Si : SiGe quantum well. In: Semiconductor Science and Technology. 1995 ; Vol. 10, No. 8. pp. 1084-1088.
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