Prof. Priya Mahadevan

S. N. Bose National Centre for Basic Sciences

Kolkata, India

E-mail: priya[at]bose.res.in,priya.mahadevan[at]gmail.com

 

Brief Bio-sketch:

Prof. Priya Mahadevan has obtained his PhD degree from the Indian Institute of Science, Bangalore in 1998 on the topic of Electronic structure of strongly correlated systems using ab-initio and model Hamiltonian approaches. She subsequently worked at JRCAT Tsukuba, NREL, Golden and IIT Madras before joining S.N.Bose centre. Her research interests are include understanding various physical phenomena using a combination of ab-initio and model Hamiltonian approaches.

ENGINEERING SPIN-VALLEY PHYSICS IN BILAYERS IN MoSe₂

Spin-orbit interactions lead to a large spin-splitting of the valence band maximum at K in MoSe₂ monolayers. However, on stacking a second layer of MoSe₂ in the same manner (2H) as found in the bulk, one finds that there is no net spin splitting. This has been attributed to the presence of inversion symmetry. As exploiting the spin splitting at the K valleys allows us to increase the functionality, an obvious route to making the bilayers useful for exploring the coupled spin and valley physics is through breaking inversion symmetry. We examined this by rotating the top layer of the bilayer by an angle θ with respect to the lower layer. While for rotation angles less than 30^o we had one type of behavior leading to a net spin splitting, for angles between 30^o and 60^o , we had a net zero spin splitting. This unusual behavior, we find, is a consequence of the symmetry of the hexagonal Brillouin zone.

This is work done in collaboration with Poonam Kumari and Joydeep Chatterjee.