Condensed-Matter Physics & Materials Science Seminar
"Novel electronic electronic phases and phase transitions at oxide interfaces"
Presented by Ramesh Budhani, National Physical Lab., India
Monday, March 4, 2013, 11 am
Bldg. 735 Conf. Rm B
Hosted by: Yimei Zhu
We have investigated the response of the two-dimensional electron gas (2DEG) formed at the interface of LaAlO3 (LAO) and LaTiO3 (LTO) ultrathin films deposited on TiO2 terminated surface of (001) SrTiO3 (STO) under the combined perturbation of electrostatic field, ultra-violet radiation, and high magnetic fields applied both separately and simultaneously. Two types of mobile charge carriers are generated in each system, having the signature of a particular type of perturbation characterized by distinctly different relaxation dynamics. The 2DEG in both the systems undergoes a superconducting transition at T < 300 mK. This quantum state of the system is perturbed significantly by carrier modulation through a gate field and by in-plane magnetic field. We see signatures of two quantum phase transitions (QPT) which can be described in the framework of a fermionic scenario for such QPTs.