Hysteresis and first-order phase transition in the two-dimensional electron gas

✍ Scribed by Vincenzo Piazza; Vittorio Pellegrini; Fabio Beltram; Werner Wegscheider; M Bichler; Tomas Jungwirth; Allan H MacDonald

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 90 KB
• Volume: 6
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(99)00068-5

✦ Synopsis

We report experimental evidence of the ÿrst-order phase transitions in the two-dimensional electron gas formed in a gated wide GaAs=AlGaAs quantum well at even-integer quantum-Hall states. At the ÿlling factor values of = 2; 4 and low temperatures, crossing of Landau levels through the application of the gate bias yields a suppression of the quantum-Hall-state excitation gap and hysteretical behaviour of the diagonal resistivity in up and down sweeps of the magnetic ÿeld. Detailed many-body calculations indicate the occurrence of a ÿrst-order phase transition and allow the determination of the exact properties of the electron ground states involved in the transition.