Ferromagnetic Mn modulation-doped two-dimensional hole systems

✍ Scribed by Ursula Wurstbauer; Imke Gronwald; Ulrich Stöberl; Anton Vogl; Dieter Schuh; Dieter Weiss; Werner Wegscheider

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 526 KB
• Volume: 40
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/j.physe.2007.09.151

✦ Synopsis

Mn modulation-doped strain relaxed In 0.75 Ga 0.25 As/In 0.75 Al 0.25 As single quantum-well (SQW) structures on (0 0 1)GaAs with an embedded InAs channel are fabricated by molecular beam epitaxy. The properties of the magnetic two-dimensional hole system were investigated by magnetotransport measurements up to 19 T in the temperature range from 50 mK to room temperature. In the lowtemperature regime typical features of the quantum Hall effect like quantized plateaus at the Hall resistance and Shubnikov-de Haas oscillations in the longitudinal resistance are observable. The resistance at B ¼ 0 T shows a distinct temperature dependence, and at low temperatures, a large negative magnetoresistance. Furthermore, a hysteretic behavior and jumps in the resistance below 300 mK and around B ¼ 0 T can be observed for an asymmetric QW structure.