Spacing and width of Coulomb blockade peaks in a silicon quantum dot

✍ Scribed by David Abusch-Magder; F Simmel; D.A Wharam; M.A Kastner; J.P Kotthaus

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 174 KB
• Volume: 6
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(99)00186-1

✦ Synopsis

We present an experimental study of the uctuations of Coulomb blockade peak positions of a quantum dot. The dot is deÿned by patterning the two-dimensional electron gas of a silicon MOSFET structure using stacked gates. The ratio of charging energy to single-particle energy is considerably larger than in comparable GaAs=AlGaAs quantum dots. The statistical distribution of the conductance peak spacings in the Coulomb blockade regime was found to be unimodal and does not follow the Wigner surmise. The uctuations of the spacings are much larger than the typical single-particle level spacing and thus clearly contradict the expectation of random matrix theory. Measurements of the natural line width of a set of several adjacent conductance peaks suggest that all of the peaks in the set are dominated by electrons being transported through a single-broad energy level.