Marvellous things in marvellous rings: energy spectrum, spins and persistent currents

✍ Scribed by T Ihn; A Fuhrer; T Heinzel; K Ensslin; W Wegscheider; M Bichler

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 502 KB
• Volume: 16
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(02)00592-1

✦ Synopsis

Magnetotransport experiments on a semiconductor quantum ring in the Coulomb blockade regime are described. The measurements allow to extract the discrete energy levels of a realistic ring, which are found to agree well with theoretical expectations. The interaction e ects important for our ring structure are analysed in detail. The experimentally observed charging energy can be quantitatively understood within the Hartree approximation including a strong screening contribution due to the top gate. The strong screening e ect is the reason for the frequent occurrence of spin-pairs in the addition spectra. The relation of the observed addition spectra to persistent currents is established and the magnitude of the current is extracted from experimental data.