School of Physical Sciences
Jawaharlal Nehru University, New Delhi
Title : Novel phases of matter in frustrated magnets: the fascinating pyrochlore architecture
Speaker: Yasir Iqbal, Department of Physics, IIT Madras
Date: 08– January -2020
Time: 4:00 p.m, Wednesday
Venue: Seminar Room, SPS
Abstract : The pyrochlore lattice — a network of corner-sharing tetrahedra — represents one of the most geometrically frustrated lattices as shown by the failure of antiferromagnetically coupled classical Heisenberg spins to develop long-range magnetic order down to zero temperature. On the other hand, the understanding of the role of quantum fluctuations in finite spin-S Heisenberg antiferromagnet represents a critically outstanding problem. I will describe the the pseudo-fermion functional renormalization group framework — a powerful nonperturbative scheme for addressing the low-energy physics of spin Hamiltonians — which has recently been applied by us to unravel the presence of quantum spin liquid behavior as well as intricate magnetic orders in long-range Heisenberg models with small spin-S. I will also present the subtleties associated with capturing the impact of quantum fluctuations, and discuss the unresolved issues. The success of the method in explaining the recently obtained neutron scattering data on the spin-1 NaCaNi2F7 pyrochlore and the spin-1/2 hyperkagome PbCuTe2O6 candidate spin liquid materials will be discussed.