Criticality and universality in strongly interacting many-body liquids
ABSTRACT :
Identification of different phases and the ensuing phase transitions is perhaps the bread and butter of condensed matter physics. Of particular interest and appeal are the universality and the critical exponents that govern phase transitions of seemingly disparate phenomena. The inclusion of strongly interacting physics into the picture makes it more novel and vibrant. Two-dimensional electrons under a strong perpendicular magnetic field leads to an array of highly correlated many-body states, the fractional quantum Hall state (FQHS) being one of the most exciting and intriguing among them. Extensive studies of disorder-induced localization have led to the emergence of a universal scaling picture in the case of non-interacting integer quantum Hall states (IQHS). However, a comprehensive study in the strongly interacting FQHS regime is scarce. Here, we report scaling measurements in the FQHS regime where interaction plays a dominant role. This study is motivated by recent calculations, based on the composite fermion theory, that suggest identical critical exponents in both IQHS and FQHS cases to the extent that the interaction between composite fermions is negligible. Finally, I will also briefly touch upon some new results that shed light on the effect of interactions and the resulting critical exponents in the IQHS regime.
ABOUT THE SPEAKER:
Dr. Pranav TM is an IIT Madras Alumnus. He was part of the graduating class of 2018, with a B.Tech. in Engineering Physics (EP). Following that he recently obtained a Ph.D. at the Department of Electrical and Computer Engineering, Princeton University, USA. His research interests are in the area of experimental condensed matter physics, especially quantum phenomena in 2D electron systems.