Non-equilibrium critical point in Be-doped low-temperature-grown GaAs

• Main Authors: Mohamed, Mohd Ambri, Pham, Tien Lam, N., Otsuka
• Format: Article
• Language: English
• Published: American Institute of Physics 2013
• Subjects: QC Physics
• Online Access: http://irep.iium.edu.my/29871/1/original_copy_manu_JAP2012.pdf; http://irep.iium.edu.my/29871/; http://dx.doi.org/10.1063/1.4790313
• Institution: Universiti Islam Antarabangsa Malaysia

We studied the transition process of antisite arsenic defects in Be-doped low-temperature-grown GaAs layers by measuring the magnetization. This material exhibits bistability at non-equilibrium; at a fixed temperature in a fixed magnetic field a sample relaxes towards two different states, depending on the preceding cooling process. We observed anomalously large magnetization fluctuations in macroscopic samples during the transition from bistability to monostability with gradual change of the temperature. Slowing down of the relaxation of the magnetization is observed as a sample approaches the transition into monostability. Large fluctuations observed from a two-piece sample exhibit intermittent bursts by high-pass filtering and follow a generalized Gumbel probability density distribution. These observations suggest a possibility of the occurrence of a non-equilibrium critical point in this material. Microscopic processes underlying the observed phenomena are discussed with results of first-principles calculations of strain fields. VC 2013 American Institute of Physics.