Quantum phase transitions studies of some low-dimensional exactly solvable dimerized quantum antiferromagnets

by Dr Rakesh Kumar (Jawaharlal Nehru University, New Delhi)

Wednesday 3 Aug 2011, 14:30 → 15:30 Asia/Kolkata

A304 (Colaba Campus)

Quantum fluctuations play very crucial role in low-dimensional frustrated antiferromagnets. As a result, the magnetic ordered ground state of a system becomes unstable and a quantum paramagnetic state emerges as the ground state. An ordered state is also influenced by the frustration which arises from the competing interactions present on the lattice geometry. Quantum fluctuations and frustration together give many novel quantum paramagnetic phases such as valence bond crystal, spin-liquid phases. In this talk, I will present quantum phase transitions studies of certain quantum antiferromagnetic spin models in 2D which show spontaneously dimerized valence bond crystal ground states. An important feature of these models is that these are exactly solvable at some special limits.