Raman spectroscopy of quantum wires and dots: magnetoplasmons and edge-spin-density modes

✍ Scribed by Christian Schüller

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 312 KB
• Volume: 3
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(98)00226-4

✦ Synopsis

We review recent magneto-Raman experiments on electronic excitations in GaAs-AlGaAs quantum wires and dots. We observe simultaneously collective spin-density and charge-density excitations (SDEs and CDEs), and also single-particlelike excitations. In a magnetic ÿeld, the CDEs (magnetoplasmons) exhibit a complex anticrossing behavior, which, in quantum wires, strongly depends on the direction of lateral wave-vector transfer. In quantum dots, we observe a splitting of the lowest spin-density mode in a magnetic ÿeld, very similar to the splitting of the magnetoplasmons. The lower branch can be interpreted as an edge-spin-density mode, where the electrons move on skipping orbits around the edge of the dot. In a microscopic model, we can identify transitions between electronic shells, which contribute to the observed low-energy SDEs of the quasiatomic system.