Wednesday Colloquia

Role of symmetry and quantum oscillation phases in few layer graphene

by Prof. Mandar Deshmukh (TIFR Mumbai)

Wednesday, October 9, 2019 from to (Asia/Kolkata)
at Lecture Theatre ( AG-66 )
2D materials are of great interest in fundamental science and applications. Few layer graphene systems are of interest as they offer interesting opportunities to study the effect of electronic interactions [1] while monolayer graphene was largely understood in terms of non-interacting physics. Few layer graphene offers an opportunity to break simple symmetries and study their consequence [2]. Our recent experiment reveals that, surprisingly, a trivial band can inherit non-trivial quantum oscillation phase from Berry’s phase of the linear Dirac band due to strong filling-enforced constraints between the linear and quadratic band Fermi surfaces that co-exist [3]. Given that many topological materials contain multiple bands, our work indicates how additional bands, which are thought to obscure the analysis, can actually be exploited to tease out the subtle effects of Berry’s phase.


1.        Datta et al. Nature Communications 8, 14518 (2017). 
2.        Datta et al. Physical Review Letters 121, 056801 (2018). 
3.        Datta et al. arxiv 1902.04264  (Science Advances in press).